Not having heard it much hereabouts (since college Spanish taught by a Basque lady) in the original "Old Spanish diluted to TexMex" spoken by "Old Guard" immigrants, 1914 or so, most from San Luis Potosi, or in the new wave of less-well educated arrivals from all over rural Mexico, it seems to remain in regular oral use in Spain. But then local usage has a lot to do with social/economic realities. I've a relative handful of Mexican American friends (a couple of guys with whom I started to Junior High 60+ years ago, a few former employees, an old lab tech whose sister worked for my parents, a retired judge and his son, the DA (both of whom rarely speak Spanish, at least in public) and a funeral home manager I've known for 50 years or so, with whom I'd use "tu" forms, or expect them to do so. "Usted" seems generally applied beyond family/friends/children.

How words or speech sound can be misleading....There's a little town near Valencia, once garrisoned by the International Brigade, Albacete, which I've heard and read being referred to as "Caga y Vete!", not very complimentary.

Then there's my screen name, bestowed upon me about 1958, while I spent a couple of months in Cordoba, VC, Mexico, with a family. The then 60ish mother in law, noting that I was rapidly balding at 18, then unusual, immediately started calling me the Spanish equivalent of "Curly". The "Sinverguenza" came later, "Shameless Rascal" or thereabouts, based on my conduct around the sheltered young women of her acquaintance. Young women in Mexico's smaller cities/towns in 1958 led very cloistered lives.