From the viewpoint of a fan of TNG, we've also got the factor of the TNG series ending on the perfect note, and the four films effectively undoing the good will that All Good Things... was built on. If TNG had ended with that episode and then disappeared into reruns, I think it'd be more fondly remembered than it is by the general public.
Thing is, that's not an especially plausible scenario - IIRC, the cast were all contracted to do a S8, but they decided to latch onto the 'buzz' you mentioned and start on movies sooner. AGT was written after they knew TNG was ending as a TV show.
Probably what would have happened at the end of S8, if they decided against movies forevermore, is that rather than ending the show they would have started doing what series like ER did and began rotating the cast out. So Stewart and Spiner would probably have quit, and they may have seen another couple either go or get cut to bring in fresh blood.
Whether Voyager would ever have happened or they'd have just moved TNG to UPN is an open question, but DS9 may have suffered from writers (and later Dorn) sticking with TNG, and no Maquis if there was no Voyager.