Hispanics do tip well, in my experience but I don’t live in California.
Not every country follows our tipping customs. In some European countries, and some south American countries, tipping is optional or maybe only 5-10%. In some of those places, being a waiter is a career choice for which a salary is paid, and tips are minimal.
I guess the part that bothers me is that lots and lots of people are insistent on living and working here but they could care less about our rules.