Personally, I'd rather have a more cohesive story, which is harder to do with optional characters. I'd especially like Vincent to have more backstory, considering how closely connected he is to Sephiroth's past. If they're optional they can't spend as much time on developing them and integrating them into they story.
I really don't think it would be that difficult. If you get them you see the scenes, if you don't you don't. Also Vincent could have backstory included regardless as he actually does have relevance to the story (and I actually stated I only have an issue with Yuffie).
Regardless, if you prefer it that way you are more than entitled to. I absolutely promise you that I will not rob you steal your identity or take any other sort of action to prevent you from buying it. I'm just not going to buy it myself, everyone else is free to make thier own decision.