The plot of TMP might be where the same men had gone before but the tone was spot on and it was cinematic, much more so the the most recent film.
It was Star Trek The Motion Picture and not Star Trek The Television Movie so naturally it wasn't going to feel the same, it shouldn't.
It's also the only Star Trek film that follows the mission statement of the series.
It's about exploration and contact with the alien.
The other films where soap opera, revenge tales, sit com or rather ham-fisted political allegory.
If Gene screwed up it was by allowing the film series to slip through his fingers and by allowing TNG to fall into the wrong hands before he died.