I am not exclusively talking about Polish board, nor am I against anyone here. I'm just saying what happens sometimes
Just because it happens sometimes, doesn't mean that there should be no local board merit sources at all. After all, local board merit sources rarely constrict themsleves to their own local board, at least from what I have noticed.
some weeks ago I noticed two guys, one from Indonesia and one from Nigeria, had tons of merits compared to their post count, got from local boards and they were posting absolutely nonsense on international boards. Probably it's my mistake that I didn't mark them because at some point I was like, I'll be a bad guy if I report them because they are from poor countries and probably it's their only way to escape.
You should have reported those posts, even though just because you think something is a nonsense, doesn't automatically mean it will be deleted as I (and probably everyone that is active reported) had my share of bad reports even though they were blatant nonsesne shitposs.