Different stores must choose (or be sent) different shipments. Up until recently my local Wally World had only car models (almost all AMT kits), no other kits of any kind unless you count Chinese-made metal F-18's with the name of the carrier spelled wrong on the decals! In the last few months they've expanded their stock, mostly with Revellogram stuff; the cars are decent but the acft are the standard 1/48 super store kits: Huey hog (the Revell 1/48 Huey is bloody embarassing), F-14, spitfire, Mustang...And definitely no Star Wars kits, though they seem to have every Star Wars lego set known to Man.
I should ask my Mom how they handle this stuff, she started at a KMart at least 20 years ago and switched to Wally World after a few years, and she's worked in the stock area so she's got to know how they're ordered..