Haven't had one that was really "bad", but did have one that was frustrating. We got into an untenable situation with an bad manager but were driven by our own work ethic to try make the park function as it was supposed to.
We worked a 6 week stint at a regional park that was operated by a non-profit group. The manager for our park (there were several in the region, operated by the same group) was never around, and she failed to hire two additional couples needed to fill all the shifts, so we were the only workers. The park had a large day use area with a lovely beach and picnic area and was heavily patronized by local families who payed $5/car for day use. We worked the entrance gate as well as the usual camp host chores and it was fun, but there was nobody to man the gate when our shift was over. Rather than leave cars full of angry families and campers lined up at the gate, we would stay on and work overtime. That soon got us in trouble with the front office that issued our paychecks, so we stopped reporting all the hours we worked, but still kept the park open so families wouldn't be disappointed when they couldn't swim and picnic on hot August days. Since the manager wasn't around, we often ended up using our own money for making change, and sometimes ended up with over a $1000 in cash that we could not turn in to the manager, who was often gone somewhere again. In the campground, we would send people to the manager's site to buy firewood, but they came back empty-handed - nobody there again. So I used my keys to the buildings to get some wood bundles and brought them to our site and soon was selling $75-$100 worth of wood every day. We also collected the camping fees from the fee drop boxes in the park, and had that money on hand too. More money to keep safe somehow. We went to see the regional manager and were told (a) we cannot work over 35 hours/week and (b) always turn money in immediately at the end of our shift, but got no answer about the lack of a manager to give it to, nor the lack of additional help that was supposed to be there to keep the park functioning. We put up with the situation for another two weeks and then gave our notice. The night before we left, another workkamper couple showed up. And guess what? No manager in the park again! The couple told us they were expected and had given the manager the date and time of their planned arrival, but apparently she couldn't be bothered to be there. I showed them around the park, gave them my keys and golf cart and wished them luck! We left early the next morning for greener pastures.
Several months later we got a letter inviting us to come back for another season, working under the same manager! I sent the head of the organization a long but polite letter explaining why we would not be back. He called to apologize for our bad experience, but did not promise to change anything. We had already lined up another gig, so we never went back.
This was a learning experience for us. We were much more careful about interviewing the park manager at the same time he was interviewing us, to make sure we wouldn't be left out on a limb again.