If you come into my house through the window and you start helping me fix things around the house or do my dishes, it changes nothing, i'd still want you out, because you came in through the window and you are prolly an irrational thief.
This illustration provides a premise to explain the situation, we are talking about illegal migrants here, they are illegal, so it does not matter what good you think they are doing or what economical benefit you feel they bring, it does not change anything, neither does it make their stay legal, so spending money to fix that is as right as it gets.
While I still do agree that everyone should live in their own nation, and only legal applications should be considered, and illegal immigration should be zero all around the world, that example is wrong. It's more like, lets say there are killers outside, and someone jumps through your window, to protection, and starts helping you out as a thank you.
I mean your options are ; send them back to where killers are, or accept the help they provide in return. But the issue is, most of them do not just help you out, they also ruin your home, and act as if they are entitled to that home too now. That is why they want them out, but also I do not want to send them back to where they had trouble, so I am a bit confused on this subject I have to be honest. I want them out, but I want them safe, get it? Not sure if that can be done, but that's what I want.