Star Trek has always, without exception -- let me say it again: always
-- worked better as a television series than as a feature film franchise. Even "good" or "successful" entries in the franchise, such as TWOK and ST09, pale in comparison to what Trek was able to accomplish on television. The format simply suits Trek much better.
As for the movies feeling like glorified TV episodes, you have to remember that, first, Trek's roots in both TOS and TNG are in television, so there's going to be that natural tendency to do things in a more TV-like manner. Second, also keep in mind that the Trek films were largely produced and even directed by people with a TV background.
Look just at the list of producers of the films: Gene Roddenberry, Harve Bennett, and Rick Berman. All of whom made their careers primarily in television. The lone exception to this is TUC, which did not have a producer from a TV background. And when you look at other categories -- writers, directors, production designers, etc. -- yes, you have some who come from the world of feature films, but you have quite a few who come from the world of television.
Is it any wonder that Trek films come out feeling more like TV episodes?