Mexico says no backsies

Mexico Sends Top Official to California Help Illegal Aliens Avoid Deportation

Mexico is sending a top cabinet-level diplomat to illegal alien-friendly California to help Mexican citizens living in the U.S. illegally avoid deportation in a post-DACA environment.

One of the things I find most curious about the immigration issue, is the official position of Mexico in supporting it. I understand why they support it (money sent back from immigrants to family boosts the economy and it also provides a way to get rid of your less desirable citizens), but that's the unofficial reason, you're not supposed to tell people that. What is the offered official reason: Our country is such a corrupt cesspool, that we think our citizens shouldn't be  forced to live here?