Maybe, but there's no way to know, because see above. It would be interesting to see the ratings of network shows that were renewed 1987-1991, that might give a better idea of whether TNG would have made the cut in its early seasons.
I'm not sure ratings would tell the complete story.
Would TNG draw as many viewers if it had to compete directly with Monday Night Football or the Cosby Show? What if it had ended up on Fox which had limited penetration during its early years? Would it have even been the same show had it aired on a network?
I agree completely, but like I said it might give a better idea.