I suspect Mexico is doing its best for its people. I doubt deliberately exports its population as a way of dealing with poverty and such.
But if we accept the argument that it is the job of the Mexican government to look after its people, is it not, then, the job of nations to look after Mexico (and other poor countries) sufficiently well that Mexicans will not want to emigrate?
OMG, I nearly came!
I expect the "Me First" brigade will quibble and wriggle and scribble their rebuttals, but that is really the final word concerning the provision of aid for immigrants.