I see the same thing, and would add they use it as a base for annual shopping pilgrimages for themselves, family, friends, employees, business partners. Status symbol and safe haven investment.
Yup - and it greatly benefits our economy. This is 100% inflow, and then the multiplier effect magnifies it further.
I used to think it was just upper-class Mexicans fleeing chaos and kidnappings, but I have been told that a big chunk of them are Mexican drug money. They are buying $2MM and up houses in my area.