I think your mileage varies considerably with some of these stores geographically.
But that begs the age old question of whether you're ignoring them, and ultimately missing out on what they DO get in?
See KM doesn't get 30 cases of a wave, they generally get one... and one sells fast here. Especially these days. My store has had the "same crummy figures" for eons too... Some CW ones in particular have hung around for quite a while (and their CW section doesn't SEEM to be stocked as frequently). But they've gotten in, and sold through, multiple cases of various waves for years and years... Like I said, I've seen almost EVERY vintage wave at my nearest K-Mart. I saw every 30AC wave there, every Legacy/BAD wave... My next nearest I visit fairly often, and I've seen almost every wave there as well now, for years.
The next furthest one I hit less frequently, but I see more or less the same thing...
Wal-Mart I'm sure will get something new here too, just they aren't right now and not everyone is swimming in wave 9 at WM is all. Same with Target. Eventually they'll get something new, but they're just a waste of time till that happens. And when they do, they'll likely overorder any wave they get as well.
It's hard to say if that's the case or not, but unless you're going to KM often (and if you're writing them off I assume you don't), I bet you've maybe missed one here and there. My KM's not shangrila or anything... It's a mess too, haha. But they're getting stuff in, and around me nobody else is except maybe TRU.