Technology evolves. When I started shooting, I wanted a blued steel and a walnut stock. Then it shifted to stainless steel and synthetic. Now everybody wants polymer, black Parkerized finish, sniper stocks, and ventilated handguards, because this is what people see on the video games and in the movies. It's the way things have naturally developed.
Underneath, though, a gun is a gun. You can dress a sheep up as a wolf, but it's still a sheep. It doesn't matter what colour it is or anything else. We have the basic criteria laid down with magazine capacity, barrel lengths, calibre restrictions. That's how you control firearms.