I failed to find where this old quote came from, but I recall being taught that for practical purposes it's best to "Understand the long words but use the short

I failed to find where this old quote came from, but I recall being taught that for practical purposes it's best to "Understand the long words but use the short ones" - even though it was intended for headlines and written communication, it's applicable to speech. The article does seem to mix up "accent" with word use though (I was going to say "conflate" but then I'd fail the above rule!) Problems with word use seem much more legitimate to raise than accent - so long as an accent can be understood, it's rarely a problem and "correcting" it is rude and unnecessary, but in cases where word use is simply incorrect and confusing, it seems fair to try to get people on the right track (politely of course). In my experience a number of these usage problems come from incorrectly inferring the meaning of a word commonly done by an overconfident speaker and much as being inclusive is nice if you use the wrong word that actually means something else it's not helpful for anyone's understanding, native or nonnative. The main criticism I would have of the article is that it doesn't really support the case that nonnative understanding is undermined by the presence of native speakers - it feels like it's just taken as given because it's easily pointed to rather than having a basis in any serious evidence. It could quite easily be that without any native speakers the nonnative speakers merely think they all understand each other.