I honestly don't care if they got paid or not. It's the "not paid and told attendance was mandatory" part that's a real sticker.
Except that's the part that is the most factually questionable from the story. The author of the article claims this was the case, but the only supporting evidence for that is a very strange and contradictory quote from some mine spokesman. On the other side, you have a direct report from the wife of a mine worker who did not attend the event and was not punished in any way. So either what they were required to attend is something other than the event *or* it wasn't really mandatory at all.
In any case, if that's the real sticker for you, this would seem to be a lot of outrage over nothing at all.