The moral of Star Trek insurrection was that genocide is okay and as long as you are white and amish,that was my and I think most people's problem with the film.
That and the fact that they stole a plan from Bart Simpson and executed it worse then he did.
If you want to understand why people don't like this movie then watch this. You don't have to agree with it or even stop liking the film but I think it should be noted that people are not just disliking this film just because they want to dislike it. I saw it in theaters and I wanted to like it,but I couldn't and this video does a a really good job of explaining why. Like I said you can still think it's the best movie and that is fine but if you have any interest in understanding why people like me don't like the movie this is your best chance of understanding.
Oh but i do agree Gremlins 2 is a hugely underrated movie.