I think, if I wasn't making them sound more absolute than they were, this is probably what they meant (been years since I read it).

I once saw written by linguist working for the dictionary in my native language, that the rules of language don't really matter.

Just adding here that it's an exaggeration for me to say "such protests have not taken place". Several activist communities did get out in opposition to Trump across the globe. The pictures look less impressive than the misinformation above but their efforts shouldn't be erased!

Absolutely. My worry would be if that's done well, or either unintentionally or intentionally taught poorly.

In principle though, teaching this is of course a good thing.

I just decided to not use the mechanic, when I couldn't figure it out.

Interesting. I'm not American and I'm not well versed in American accents, so I didn't catch that.