Lots of reasons:

1. Traditional Hispanic families generally don't allow their daughters to go away to college. There are actually quite a few qualified students in the area that A&M has tried to get to main campus unsuccessfully. Since they (along with everyone else) have failed in getting the kids to the school, they are bringing the school to them. (t.u.-RGV is the worst performing school in the state)

2, Along with #1, educating Hispanic girls is extremely effective at keeping them from starting to pop out many spawn as soon as they're done with high school and ending up on public assistance.

3. Available grants to serve minority and impoverished populations.

4. Goal of providing education to a population without much of it.

5. Sharp thinks bigger is always better and that the on-main-campus Aggie experience isn't very valuable.

6. As with the Rellis Campus, the quality of Aggie grads is not as important to Sharp as the quantity of Aggie grads.

7. Political aspirations by the system to have influence over a demographic that will take over politics in the state within the next decade or two and will control how funding is distributed.

I don't necessarily support any of these, just telling you why they're starting the new RGV campus.