Nemesis I think was intended as the TNG equivalent of VI, a proper farewell, not a comeback with more sequels to follow. The difference, besides the quality which we all know is subjective, is that in VI, Paramount gave it a very small budget (I heard Meyer had to fight for every penny) and Nemesis got a blank-check. So right from the start they raised the stakes so that the film had to pull James Cameron style numbers when the franchise was clearly dying after suffering the dud of insurrection and then waiting 4 years.
When I found out Nemesis was coming out I was shocked, because usually it doesn't take that long to have a sequel. The franchise was clearly dead for a while and there was some sea-change at the studio that made them want to resurrect it one last time, but you can't just let a franchise wither like that and then raise the Titanic.
So I think the odds were against it ever being seen as a success on the part of the studio, even if it had been rated as highly as VI.