What makes sighthounds so unpopular??

I think it's their not so biddable nature. They're not as trainable as say, a retreiver. They don't tend to have reliable recall. I would LOVE to have a retired greyhound, or a pharoah hound, or  a saluki, or even an afghan. I think sighthounds are GORGEOUS and I admire their beautiful elegance. Emma thinks Italian Greyhounds are prey, so I can't have one of those

My guess is the trainability level, and the fact that they're not small and cute (except IGs and Whippets).

Trainability is definitely not a sighthound strong point.  But are some of the really popular breeds any better?  Bassets and beagles (#5) are just as bad or worse, as are Scotties (40), bullmastiffs (#42), bulldogs (#13) and a number of other breeds that are far more popular.  So, I think there must be more to it than that.  Do you agree?
 
As to small and cute - that would be an issue as well.  But what about rotties, GSDs, mastiffs and bullmastiffs, which are way more popular than deerhounds or borzois?

Perhaps it's their reputation for being predatory with cats or their less than stellar reputation for coming when called.  Of course, that's just generalization.  We know that some sighthounds are great - Patty Ruzzo showed her Whippet in competition obedience I believe, and the frisbee catching Ashley Whippet is quite famous.
Also, most families adopt dog breeds that are perceived as friendly with kids, and these breeds tend to be regarded as somewhat aloof and not human-focused, like the working, sporting or herding dogs.

Two good points, Spirit, though I know many terriers, GSDs, etc that chase cats.  The "good with kids" issue is probably a factor, though look how popular Scottys are and I don't consider it a child-friendly breed.   Still, I think you are right when you say people see sighthounds as cool and aloof.

They are big, and muscular. Look at all the un-exercised daisy (designers) who have no exercise. Many do poorly off lead because of all the rabbits and "game" they were breed to chase. 

though I know many terriers, GSDs, etc that chase cats.

True. JRT are KNOWN for being horrible with cats and kids, and being "untrainable" (I have NO idea who came up with that. Obviously someone who wasn't so persistant. A good hunting dog HAS to have a strong "leave it" and recall) and they're a pretty popular breed. I wish they weren't. They more than make up for their cuteness with BADness

Your're right - sighthounds being off leash is a big no-no.

I'm not sure that Scotties are very popular with *young* families.  Just going by breed stats can be misleading.  To be honest, I see very few Scotties in my classes.   We're in a horsey neighborhood, so there are a lot of JRT's, and the ones who attend puppy class whose owners do their homework seem to do very well.  The ones I hate to see coming are the 8-9 month old pups who are now starting to drive their owners nuts!
 

I would prefer a sighthound to someof the other breeds mentioned here.  I like their regal looks and their independant natures.

Sighthound pups are relativley expensive, so maybe that's part of it.  I am not sure!

I think it's just a combination of things that everyone has mentioned:  if you get them from a breeder they can be very expensive (I know that RRs can cost around $1000 at least), they need a ton of exercise, they are known for not being good off leash, they are considered "prey driven" so many people with kids think (often mistakenly) that they won't be good around kids, and most importantly I think is that you just don't see them as much as other more common breeds.  People see lots of labs, retrievers, rottweilers and what people see out and about they are more apt to buy, just because they are more familiar with them.
 
Caesar is an RR (although I've read some debate as to whether they are a true sighthound) and I had never even heard of them before - we adopted him after a family member couldn't take care of two puppies at once. You just don't see RRs or whippets or greyhounds walking around neighborhoods like you do the more common breeds.  And I would love, love to have C go off leash when we go on a hike, but I would never do it. He sees squirrels and he's gone. But he's great with kids and cats . . .

This was posted on another board but I'll respond here as well. I believe sighthounds aren't popular, which is a good thing in my opinion because look what popularity has done to some breeds such as Dalmatians, because they can be very tall and they can be aloof. A lot of sighthounds would rather do their own thing than interact with the family and some aren't interested in rolling around with children. Then you have aesthetics... people are used to "fat" dogs and a skinny sighthound turns people off. Ask Debbie who is a member here and owns Saluki's at how many times Animal Control was called on her because she's "starving" her dogs. I think sighthounds can make excellent pets, although the ones I own didn't work out right, but as with all breeds... they aren't for everyone.
 
When it comes to price, I was extremely shocked at how "cheap" Borzoi were at the time I owned them. I paid $500 to $700 for pet and show quality. That's way cheaper than the purchase price of Boston Terriers. [] While I think the price is somewhat cheaper because they do have large litters and normally don't require c-sections to deliver, I also think price depends on the rarity of the breed. While Borzoi price isn't that bad.. I could expect to pay big time money for a Pharoah or Ibizan Hound.

I believe sighthounds aren't popular, which is a good thing in my opinion because look what popularity has done to some breeds such as Dalmatians,

I agree. Popularity has ruined quite a few good breeds, including Labs, Cockers, and Poodles. All  three of those very popular breeds are awesome dogs, when bred properly. All three can become horrible in the hands of BYBs. They're riddled with serious health and temperament issues, and they shouldn't be. They're all supposed to be good tempered family dogs, and hunting dogs.

Yes, I do think it's a combo: the off leash issue, being skinny, being aloof, hard to train, not great with kids (only saluki/borzoi and maybe afghan), rare (though this begs the question).
 
A few objective pluses: low upkeep (esp. the shorthair breeds), nonbarkers, shed little (shorthairs), no doggie odor (whippets/pharoahs), great in hot weather, relatively ailment free (except skin issues with whippets and greyhounds), undemanding re attention, easy on the house/furniture.   Scottish deerhounds may have the best disposition of ANY breed (I realize this is subjective).  
 
And yes, being rare does have some advantages.  

In addition to everything mentioned above, I'd also add that (thankfully) the SH's haven't been seen in the movies or on TV or had much press.  Look what 101Dalmations did to that breed.  JRT's have been seen in Frasier, Wishbone, My Dog Skip and who knows what ever else.  The Taco Bell commercials and fameous people have helped the demand for chi's. 
 
Also, SH's don't fawn on their people.  Most look at you like you're the household staff.  Most people don't want that in a dog.  They want an obedient, easy to train animal.  People also want an -est dog.  When Coren's list came out, lots of people wanted a border collie becasue he said it was the "smartest".  (Of course they didn't do any homework beyond that.) 
 
And some of the appearance is simply in the numbers.  You're comparing 12 breeds of SH's to 27 different breeds of terriers.  You could also ask, why one of the most well known breeds in the US, the American Foxhound, has consistantly ranks at the very bottom of the popularity list. 
 
And of course, what's in today, is passe tomorrow.  Cockers, GSD's, poodles, St Bernards, even smooth fox terriers, etc have all had their day in the sun, so to speak.  Who know's, perhaps in 10 or 20 years a SH may be in the top 10 in AKC popularity rankings.  I read that basenjis were 10 or 11 in the DC area.  (cringe)