The gun on top is a military issue gun. It fires a larger, faster round than gun #2 (even if it weren't a paintball gun). But #2 is black and scary looking. So there must not be any legitimate use for it.
Both guns do the same thing. But #1 can kill you from farther away. The difference is purely aesthetic.
As for the question posed, why not ask the millions of people who own and use guns like #2 and who never commit any crimes with them. You'll get plenty of valid answers.
