I'm just a grad student (but I've seen plenty of paper reviews and heard plenty of discussions at conferences), but at least in my corner of academia, the older and more established folks tend to be more visionary: they're more distant from the publish-or-perish scramble of assistant professorship and they've seen cycles of fads come and go. Of course a lot of younger profs bring fresh approaches too but IMHO the tendency to conform to 'accepted' topics to survive is much stronger on the early end of a career.