Because they have no incentive to? Not sure what that question has to do with my response.
I'll try making my point in a different way. You seem to have some kind of resentment for undocumented immigrants because you went through a long immigration process and they didn't, and now you both work in the US. My point is that the facts that you're both immigrants and work in the US are the only similarities. They have to work hard jobs for little pay, and look over their shoulders for their whole lives knowing they could be locked up at any moment. They're not getting the same reward that you did for going through the immigration process. You don't have anything to be resentful towards them about.
I'll try making my point in a different way. You seem to have some kind of resentment for undocumented immigrants because you went through a long immigration process and they didn't, and now you both work in the US. My point is that the facts that you're both immigrants and work in the US are the only similarities. They have to work hard jobs for little pay, and look over their shoulders for their whole lives knowing they could be locked up at any moment. They're not getting the same reward that you did for going through the immigration process. You don't have anything to be resentful towards them about.