Agree to disagree about the quality of Star Trek VI. That aside, Star Trek VI was crafted by Nimoy and Nicholas Meyer with the intention of it being the grand finale of TOS. Nemesis was not intended to be Next Gen's finale by either the filmmakers or the cast. The tagline of the movie was "A generation's final journey begins.", which Stewart and the others made abundantly clear while promoting it meant that they were planning to do a least one last film following Nemesis.
I don't recall anyone saying anything about continuing on after Nemesis back then. I don't recall ever thinking it was anything BUT the final movie with the TNG crew and it seemed crafted as just that. Just like the show held the characters pretty much in stasis until the final ep, so too did the movies until the final one. Riker and Troi got married, Riker gets his own ship, Data dies, don't really remember anything about Geordi, somehow Worf went from prestigious Ambassador to guy firing the phasers.....even Wesley showed up. Picard stays behind and welcomes a new first officer. It was just like your typical last episode of a t.v. show where all of sudden half the cast is moving on because they're not going to be making the show anymore so you can finally have them move on with their lives.