Yeah I think TNG was really into that one eyed devotion to starfleet and the working to better yourself ideal in a way that wasn't as much of a driving force for the other shows. The Roddenberry grip.
DS9 had the advantage of showing the characters on a mini settlement and had major characters completely outside of the starfleet/humanity ideals. This was very enriching to character development and just plain more interesting to look at.
A starship is a sort of mini settlement. Espically in the case of VOY were it was possible that you would be spending the rest of your life with the rest of the crew.
Yes but it's a mini-settlement of people in the same organization with the same ideals who even went to the same school! Can't compare that to DS9 with it's mix of races and civilians from all over with agendas that have nothing to do with starfleet.