Hmm good point. I've thought about that but perhaps it is a landing craft or a transport ship? Also, people might want them for their AU or marine forces. Plus there are amphibious tanks too!
(and I'll post a bunch of those)
But apart from all that, I've just noticed that people do dibbs and dabs when it comes to SB scale vehicles and some of them look pretty bad. On top of that, people post FD scale tanks and stuff, why not SB scale? They would look good with all the aircraft on planebucket.