I don't think they were fucked over by the US so much as their own politicians, though. Their government could have said "we're not gonna sign NAFTA unless there is generous visa-free flow of non-criminals across the border" or whatever and honestly I think they could have strong armed America into agreeing to it, we're "greedy" enough we would have went with it.
https://www.latimes.com/archives/la-xpm-1995-05-20-mn-4009-s...
It's absurd to suggest Mexico could have strong-armed the US.
When Mexicans can come work in the US they generally have to be paid more (at the very least due to minimum wage). So we'd be angry because now we're competing against.... more expensive labor? It's not the voting masses of people at the bottom that benefit from current policy, it's those at the top. NAFTA is the worst of both worlds for labor on both sides, which makes it democratically unattractive.