I still don't understand why it was such a big deal...

I get that blackface is an issue in bigger productions because yeah, they should really cast a black actor instead of putting makeup on a white one, but this was (as I understand it) a high school play where an actor of the correct race was probably not available (I know it would've been hard to find where I went to school), and even then, it most definitely wasn't a paid gig, so the issue around stealing jobs is completely moot.

Is it insensitive? Oh yes. Is it actually hateful towards black / brown people? I don't think so.

"They should learn the value of hard work" is on a completely different level, IMO. As if they don't work as hard as anyone else.