Probably because, contra "diversity", they're similar enough. From where I sit, Hispanics, regardless of national origin, are quick to file fraudulent, groundless or wildly exaggerated lawsuits. I just had to postpone a deposition because the plaintiff has gone back to El Salvador for a while... next week, it'll be a plaintiff in Guatemala. Apparently, their injuries aren't so bad that they can't skip back to Central America for a few weeks here and there.
And, there's money in it. Juries in many jurisdictions will fork over the cash to these folks, especially when there are fellow Hispanics on the jury.
All of which raises some questions: are lawyers really doing America a favor by marketing to Hispanics, thereby encouraging all the frivolous and costly litigation? Are Hispanics really doing us a favor by pursuing the claims?
The entitlement mentality fueling the lawsuit craze is bad enough when restricted to English-speaking American citizens. But tossing in the ethnic angle only makes it worse.