I just wanted to add that this is not the fault of the Mexican government, it is US policy.
Relatives and spouses of US citizens or permanent residents can apply for the visa. It is a very lengthy process, right now they are working on applications from 1992 .

Mexicans wait longer than any other nationality for the visa process. It also cost over $1000 just to file the beginning paperwork, which is way out of reach for most Mexican immigrants. That does not include medicals, fingerprints, other processing fees, or DNA testing. DNA testing is becoming more common...I just paid $3000 for my husband's kids to be tested.