Lets just say that the theme song is so bad, that I was burning through every Star Trek show my first time watching. Next Gen-Boom, TOS-POW, Voyager-Ehh OK!, Deep Space Nine-WOAH. Then when I got to Enterprise I had such a visceral reaction to the theme song on the first episode that I never continued the show. Its a very stupid reason I know, but its my reason, and I am going to need a much more compelling reason ever to return.
We need a "Star Wars Despecialized Editon" of Enterprise where the only thing they change is the theme song.
Edit: Alright everyone you talked me into it, my local library has the Enterprise DVDs so I'll give them a go. And I'll even listen to the theme song. 🖖