I think it was because there was just so much Trek on at the same time. There was a TNG movie series running concurrently with DS9, VOY, and ENT, so unless there was a crossover film, the TNG film series would have to run its course before the other shows got a shot. And it didn't until ENT was deep into its run. By that point, the last film was Nemesis, which didn't perform well, calling into question the viability of, at least Berman-run, Trek on film.
I don't exactly agree with this, but it does remind me that INS was the real Trek-killer (IMO). So much audience good-will built up with FC, and they just pissed it all away. (Could probably make the same argument for VOY.)
The way they should have looked at it is that the movies are advertisements for the TV series, and vice versa. (The same way a band's live shows advertise the records, and the other way around.) So instead of Pillar getting nostalgic for the least cinematic aspects of TNG, he should have focused on (a) blowing the audience away, and (b) selling the new TV characters to the movie audience as interesting potential leads.
The TV series did try to reference stuff from the movies and TNG, but the relationship was not reciprocal. If it had been, perhaps we might eventually have seen movies based on other series.
I just had an idea for an alternate TNG movie, in which our heroes have to shepherd a convoy of refugee spaceships through hostile territory. Captain of the convoy is one Kira Nerys.