And those people should be coming to America because?
Possibly the same reason you are in America, whatever that may be. People gotta be somewhere, and America (in spite of our embarrassing fuckwittery) has a lot of great things going for it. I realize it's subjective and we all have different opinions, but it's not unreasonable for people to prefer America. (And yes, it's not unreasonable for someone to prefer somewhere else instead.) We really do have our attractions. If you don't think those attractions make us the right choice for you (or someone else), that's fine, but if you don't think they exist then you're too dumb to be talking to.
If you can't think of a reason for choosing America, go ahead and leave. Plenty of people will be happy to take your place. Everyone can be a winner, even you.