At this point...it's whatever, honestly. It's been a ridiculously long, conflicted development cycle. A lot of these people left the project probably because they needed to justify getting a paycheck, to find an avenue for productivity, or simply because no one works on a single thing for that long. The "dream team" is an illusion now, anyway. All the people who made those amazing games spent an entire generation so far removed from those heights. There's no guarantee that working within SE's current corporate environment, within the industry as it is today, and with modern technology, that they would strike gold again.
Versus XIII has never been more than an idea, whereas FFXV is something that's actually happening. I'm interested in seeing what SE's newer faces are capable of. "God, these trailers were so emotional" and "man, this game person x made in 1998 was wonderful" aren't the greatest justifications for holding onto the past.