To be fair, native speakers often act like "you slightly mispronounced that word in the sentence, so I have literally zero idea what any of it meant and am doubting your intelligience"

It's very frustrating in Polish, for example, when I forget to roll my R's (difficult with my lisp!) and somehow I'm talking alien nonsense.

Agreed. The focus on error-free communication at the early stages is what I think turns off a lot of would-be language learners. I like the idea of only correcting learners when really needed (i.e. when their message can not be understood) but letting the other stuff go (used the wrong preposition? don't worry about it. he/she will pick it up as they progress)