It should be as clear as a bell that if you live somewhere for 80 years, maybe even longer if they started coming post 1890, that's over 100 years, that you might not just pull up stakes and leave. The danger may have creeped up on them. So, no, I'm not going to blame them. If they came in 2005 or something, I might consider that point of view.
They apparently have some lucrative pecan orchards. Maybe some even had some sea-side property on the coast from what I read.
No, I'm not planning to go to Mexico and wouldn't. But I'm not so quick to judge others either.
And I'd suspect a lot of that 80-110 years has been peaceful. Some maybe not, there was a revolution in Mexico, too, they threw down roots as well.
Even the settling of a lot of America was not always a walk in the park. Some saw some very tough times, I'm sure.