Maybe the possibility of things having gone that direction is just too disappointing for me to contemplate. With enough blame to go around for what happened to ST, I'd just rather hope the people involved would have known better next time. It's hard to picture Nem making $100 mil though; if I recall most of the speculative talk was doom and gloom throughout the film's development. Although we probably expected it to still perform 'somewhat' better than it ultimately did.
It seems to me Countdown did exactly what you described with B4/Data, right to the T. I call foul. From the movie itself, I read it as B4 being Data's autistic older brother who was never designed to be more than an unsophisticated prototype, getting a chance to be reprogrammed instead into Data's son. Somewhat akin to the 'remember' bit from TWOK, implying that not 'all' of Data had been passed away. Though admittedly too much of the film was derivative of TWOK anyway. Even the way I read it, actually following through with B4/Data in another 'strait' TNG film regardless of how Nem did I think would have been a serious mistake.