I still do like the game despite it's weak points. Mainly because at the time 9 year old me was wooed with the animation and pure wackiness of the it's characters.
Nothing wrong with that. Recognizing something's shortcomings, especially in the things we love, is a very good thing. Some of the things I love the most have glaring, obvious flaws, and in some cases are entirely part of why I love them so much.
I'll readily agree that Earthworm Jim isn't on the same level as the games you listed, but I wouldn't call it middle of the road. It's much better than stuff like Vectorman or... really, anything else western developers produced during that era. It doesn't feel entirely precise at times, but there's a good flow to the gameplay and a lot of cool ideas in each level that are implemented well.
Edit: That said, I'm curious how much the version one played of EWJ affects how they feel about it now. I played the Windows 95 version, which was great and had significantly better animation than its console counterparts. Might've made some of the difference.
Why I went with a not very approximate description like middle of the road. I won't put up a fight with anyone who considers it above average. Not like there is a way to measure this stuff in a real way, despite what review systems try to accomplish. I'm not exactly on the side that believes a game must have tight, precise control to be of notable worth, but when you are operating in a genre and era where that particular aspect really excels, it is hard not to be a little more critical. There are always exceptions that break all sorts of conventions.
Something like Super Metroid doesn't just
feel good to play, it does that and also has incredible cohesion between that and its aesthetic. You feel like a bad-ass space bounty hunter, and every single thing you see and hear backs that up with master precision.
Had Earthworm Jim pulled off that level of craft it would have really been something, like holy shit can you imagine? But it doesn't. It is a decent action platformer with a good sense of humor, for the time, and some killer illustrators/animators on the team. Maybe those last two points really propel it up for some folks. Nothing wrong with that.