I can read and speak Spanish; I learned it in school, but I am not a native speaker. However, it seems like a sizable portion of the signs I see have glaring orthographic and grammatical errors. Like this subway ad that I recently photographed:
(link goes to full size)
I can count four accentuation errors and two grammatical errors (switch from Usted to tú form; vacúnase instead of vacúnese), and I might be missing more. And this is an advertisement commissioned by the government, so presumably it was professionally translated. I continue to see ads that are as bad as this or worse everyday, and only very rarely do I see English ads with similar levels of mistakes.
So I guess what I'm asking is... what sort of factors cause this sort of inattention to rules? If this was a casual note from one person to another, I'd understand, but they're advertisements that cost tens of thousands of dollars to display. Is there a general problem with or loosening of rules for orthography in the Spanish language in the United States? Are there just a lot of careless translators? Or... what?