Actually you cannot show that a couple decades of massive uncontrolled immigration has done the average Mexican back home any good at all --- the country is worse off than ever, and the misery is only growing.
Uncontrolled immigration leads to even more uncontrolled immigration --- people don't work on fixing their homeland. It just makes the situation that much worse.
Why would I want to? I don't care about Mexico except when I go there for vacations, and it isn't my first choice, just cheap and convenient.