INS is a victory lap film released during a time of high competition. Berman and Piller both thought that going softer after a red hot, go get'em action film like First Contact would help sustain the brand. They deliberately avoided doing another crowd pleaser like FC. They avoided doing a Dominion War film. Because Piller was over the story and wanted something optimistic. They deliberating avoided doing a Heart of Darkness/Apocalypse Now style film. Because that would've been too dark.
The people at these studios are not dumb. They are constantly paying attention to what the competitors are doing. INS was the wrong film for the wrong time. It's just a bad two-part episode that was released in theaters.
GEN is bad for the same reasons as INS. However, GEN gets a pass because it was released during the height of Trek's popularity in the 90s. Coming off 7 seasons of TNG, 2 seasons of DS9 and a few months before VOY. One of the lessons Berman, Braga and Moore took from GEN was to not take the audience for granted. The pay per view nature of the movies can make or break you. Unlike TV, there's no coming back next week to give it another shot.
INS has the reputation it does because there's nothing in the film that merits revisiting, debating or praising. Franchise fatigue from unexciting stories did Trek in during the 90s.
It was shrewd to not keep the record needle stuck in the groove with endless action shtick.
INS was definitely an unexciting mess*. It had a couple solid set pieces and a bunch of ideas, but none of them gelled and some led to more questions the more you think about it. The idea of a species whose kiddies all rebelled against pops and ended up with their own set of arrogance and other problems really isn't told well, nor is the revelation exciting - or worthwhile. The movie goes so far to prop up the Baku by not only Picard doing as serious in this movie what he joked about in the previous one, but even tells and shows Starfleet doing the "needs of the many over needs of the few" as if it's always a bad thing to do. It made Picard damning Sarjenka and her planet to death seem tame by comparison. No Trek flick up to this point was so brazen or deliberate in missing the mark, and no later movie or tv show was anything approaching apocryphal either. (Even V and VI, for all their misfires, don't come close.) For every idea that could have been interesting, something else is quick to show it really isn't.
Even the Sona ship sets came from DS9 episodes; usually the newest shiniest movie will create sets to be reused down the food chain, and not the other way around.
Definitely franchise burnout and rot while throwing everything into the pot and without any meat to it, Complete with self-destruct mechanism, which makes less than zero sense... I've no clue how anyone could think that singalong would be the next big fad as well... at least it had the virtue of never being tried...
* I like the dogfight and the Ru'afo speech about "If Picard or his crew meddle, eliminate them" but in all fairness, that's F Murray Abraham turning something cliche into something halfway decent thanks to good acting. The cast is solid in this, but F Murray wasn't able to save the movie on his own and he's not in it as long as he'd have to be either. Never mind that dumb*** ending. Even Kirk extended his hand to save Kruge - you know, the Klingon who brutally murdered his kid and was going to use Genesis as a tool to extort, blackmail, reverse engineer, destroy, and other nice things and due to** paranoia and not believing that his empire's rulers were genuine in working toward peace with the Federation. Sheesh. Ru'Afo, who wants the radiation in belief that he and his buddies can be healed while not having to be tethered to that planet (and with the Federation getting to help all its 10 zillion people as well), is given that Picard look and only serves to remind how Picard is often overrated and quite nasty as a character, elevated by an actor of also great-caliber (Patrick Stewart, who made a lot of season 1's (lesser material) better than it deserved to be as well. Hmmm, there's another subplot - how sincere was the relationship, but the movie couldn't make up its mind if it's a handful of naughty admirals or all of the Federation as originally claimed or so on... definitely franchise rot... )
** if memory serves. Thankfully, III (despite its imperfections and no movie is ever going to be 100% perfect so I try not to lose sleep over most of them) is a far more solid movie and has far less to nitpick in terms of plot logistics and holes.
