I'll throw another theoretical hand-grenade out there: one of the things which arguably sinks the TNG movies like a stone (floatational Data optional!) is that they're all stand-alones. Look at the TOS movies, and every one of them from TWOK
through to TVH
(and possibly even TFF
, thematically) are telling what we'd now call a 'story arc'. Each movie builds on the ending of the previous one, the story develops and the Trek universe feels much larger as a result. It's theatrical story-telling for theatrical movies.
Contrast this to TNG, where every movie stands alone in and of itself, with (probably) the only link being Riker and Troi shagging in Insurrection
leading to them getting married in Nemesis
. The reason we so often hear the TNG movies being described as "double-sized TV episodes on the big screen" is because, limited as they are to self-contained plots, they feel
like they've been written for television. First Contact
being the one exception.