^Pretty much sums it up. You will get abuse, you will get angry guests and you will get complaints, probably many of them. But on the flip side, you also get so many people who enjoy themselves, so many people who interact with you and want to talk to you, ask you questions and are just generally very pleasant towards you.
The best thing you can do is try and drown out that abuse with the thoughts of those who enjoyed their time there. People seem to forget that others who work at the park are human, so they might be having a bad day, or that there are rules that everyone has to abide by that they want to pass, maybe to get a quicker ride than others (On a particular ride I operated, there were actually 4 ways to get to the station, only one of them being the regular entrance with the queue, but people would come down every pathway and claim they 'didn't know' and try get on anyway).
Another thing to point out is that most people who work at a Theme Park are only doing so temporarily. Even the assistant managers and area managers, they very rarely stay there for years on end because it's not a reliable job to have, and the work you put in is so huge compared to what you get paid, so like the above poster said, you have to really want to be in the industry to work somewhere.
One thing to note though, and I'm not sure if this happens at every park but I know it certainly happened at the one I worked at, is that favouritism is everything. The assistant managers have their favourites, and those favourites are the ones who will get the new rides, or they'll be the ones who get the best jobs to do. Of course, favouritism happens everywhere, but so much more so at theme parks from my experience. The fact that it's a seasonal job also means that you don't have job security, so you don't even necessarily have to do anything wrong to lose your job, you just have to be disliked by a manager.
Honestly, I'd say that it's a job that people should have at least once in their life. It is fun in parts, but it is also incredibly draining, very bad pay for the hours and effort required, and you just aren't appreciated, as an employee by the higher ups, or as someone who works there by the guests. Managers know that they can replace you at the end of the season with someone new, and guests seem to expect you to be some sort of robot most of the time, expecting nothing to ever go wrong. But, I wouldn't say to be in that sort of job for more than a couple of years at most, it's not a job anyone should aspire to have for their whole life.