We experience this pretty regularly over in GW2 all the time. It’s one of the reasons why, even though I enjoy a public event every now and then, I have to take breaks from them without getting annoyed with how lazy people are. The open world meta events are pretty easy, but because of how many people just tag and leech the event they end up taking a lot longer than they should (and sometimes even fail).
The way it works in gw2, time = money even moreso in wow, so it just really creates an annoying situation for anyone who is actually trying to get through the event and onto the next. People get maximum rewards for doing literally nothing…cool beans.