I took three years of Spanish and got an A every semester. Even when it was still fresh in my mind, I was nowhere near able to hold even a very simple conversation. And now just a few years later it's all totally gone from my brain.
My mother's native language is Spanish and she never taught me, which I resent her for. But I still find it incredible how shitty my public school education in Spanish was. We really should be teaching kids a second language from kindergarten up.
I think it depends on the instructor. It's just an issue with how poorly the textbooks are created where they cast a wide net over all of spanish without giving enough linguistic context.
True, even within Latin America there are many big differences in dialect. Though I'd obviously prefer Mexican Spanish, I'd still take any of those over the Spanish that's regulated by the literal, actual crown that still exists for some reason. (la Real Academia Española)