Re: Evens good, odds bad only applies to the first six
Bullpuckies. ST:TMP is an over extended episode but at least attempts to tell a science fiction story. Wrath of Kahn is fine, granted. Search for Spock isn't bad, even though it turns reintroducing a dead character into a 2 hour film.
Voyage Home hasn't stood the test of time at all. The plot is the worst kind of eco bollocks going, with the tilt towards humour strained and forced. "It's funny because they don't know how 1980s tech and culture work!". Final Frontier is just awful with little to nothing to redeem it. Undiscovered Country for my money is the best of the original cast films; acknowledges their age and has them questioning their relevancy, together with a plot that deals with concepts more than spectacle.
So, we've got one decent science fiction film that sorta works as a trek film, two bona fide good films (II & IV) and bobbins for the rest.
Generations just plain doesn't work. The plot around the Nexus is awful (see RedLetterMedia's considered, snarky takedown on YouTube) and exists solely as an exercise to have Kirk and Picard interact. The trash the Enterprise again is straight out of Search for Spock, leaving aside the nitpicking around shield rotation frequencies the characters had already solved in TV TNG.
First Contact appears fine but makes the mistake of taking a well defined hive mind, decentralised enemy and giving it a focal point/weakness: the Borg Queen. cf Davros in WHo for what happens next. The previous implacable enemy become a bunch of hapless stooges around a shrieking figurehead.
Insurrection was awful if for no other reasons than the observation planet of youth making female crew members boobs firmer. Seriously? The worst kind of pandering to the 7 of 9 fancying demographic. If TNG was the best embodiment of Rodenberry's vision then Insurrection was that vision subverted by morons.
Nemesis I saw at the cinema and aside from yet ANOTHER Enterprise destruction I couldn't tell you a damned thing about the film. It utterly failed to register.
Aside from DS9 which got better as it went along, everything that came afterwards was just terrible. Voyager had a great over-arching premise; far from home, few resources, no Starfleet/support infrastructure and intra-crew hostilities. All established in the opening episode, all ignored immediately thereafter. The so-far-away-from-home crew ran into more familiar faces than they would have back home, had no end of magic resource/shuttlecraft replacements and payed no attention to the dramatic potential of its overall premise. The episodes in the main were either warmed over TNG, or at worst were Brannon Braga spatial anomaly of the week where Yesterday's Enterprise was written to the tune of diminishing returns every time. Add in Daisy Duke/Heather Locklear/7 of 9 and I soon checked out. The BSG reboot took the premise of Voyager and then actually made something of it, albeit in a grimdark way that wouldn't have been Trek.
Enterprise was even worse. I never got past the pilot. Characters lubing each other up, THAT theme song and more ignoring your own premise - humanity's first trip outside of the solar system evokes absolutely no wonder or sense of occasion, instead becoming a FedEx run to deliver a Klingon back home - and all hope was lost for me.
Paramount/Abrams can do whatever they like with Trek as far as I'm concerned. Braga & Berman flushed the Trek premise around the U bend once DS9 went it's own way under separate stewardship, pandering to the worst aspects of its own fandom.
Apologies for the rant, but none of the TNG films are actually any good or are particularly consistent with the TV series that spawned them, either tonally or premise wise.