And that explains it all right there. If you thought the entire Disney park was terrible then, well, you wouldn't find anything at all enjoyable there. It sounds like theme parks just aren't your thing, and they're certainly not for everyone, I myself have met people that didn't have fun at Disneyland or Disney World (even if I can't possibly figure out how you couldn't have fun there, but to each their own)... But there are millions of people who do love the Disney parks, as has been proven for decades, so the parks are definitely safe in that regard. Theme parks just aren't for you and there isn't anything wrong with that... But again, that's not the park's fault, that's your own fault. No theme park can convince you that it's a fun place to be, you have to make that decision all on your own.
Having an open mind is an important thing because if you go into something with an open mind then you can experience that thing without any preconceived notions of it-- you might end up liking that thing, or you might not, but you would never know without an open mind. How can you possibly enjoy something if you go in with the attitude that it's going to be terrible? If you go to watch a movie after having convinced yourself that it's going to be a terrible movie then it's going to be a terrible movie for you. If you're given a new food to try but you've already made up your mind that you're not going to like it, then when you do try the food you're not going to like it because you've already convinced yourself that you're not. If you go to a theme park already convinced that you're not going to have any fun there then guess what? You're not going to have any fun there. It's all about your attitude and how you go in to new things.
Keeping an open mind leads you to new experiences and to new possibilities, and to things that you never would have guessed that you would have liked. If you had went into Galaxy's Edge without already convincing yourself that it was going to be bad, if you had gone in with an open mind, then things could have been very different. You may have still disliked it, sure, but you also might have liked it after all. You did yourself a disservice by closing your mind to the possibility that you might actually have fun there and by not giving it a chance.