I'd say that is not true anymore - it used to be pretty hard to buy games before (with retarded regional restrictions and no Steam, etc). So people couldn't be assed to buy a game if they could not find a cracked one.

But today, you can do it with a few clicks, so if someone really wants to play a game because it looks cool/interesting/whatever, I'd say a lot of people will just pay for it if they can't find the crack.