Pitt may not have fielded teams competitive enough to win a national title, but that is far different than being not being part of a system where a national title pursuit is theoretical possible. And the possibility was evidenced by the fact that even WVU had a shot at it when they were in the Big East, if not for 13-9. Heck, Pitt wasn't that far from a playoff bid this past season. If not for WMU, they might have gotten in.
If Pitt isn't part of the perceived upper echelon, I think many diehards will fade away, because being in that upper eschelon, whether teams on the field were good or bad, is what has been historically expected of Pitt. Pittsburgh does not easily embrace teams of minor league status, which is what a conference of left overs may become perceived as.