Loc: Poughkeepsie, NY
True. Generations of climbers soloed down Silly Chimney. But solidity on easy ground, nowadays the mark of someone with mountaineering experience, is no longer a given for all climbers.
Many now learn to climb hard without ever climbing easy, and many never actually climb down anything, and so there is now a significant group with no experience in unroped scrambling or unprotected 4th class leading.
Rappelling looks safer to these folks, and maybe it is, in spite of all the accidents involving bad anchors and uneven ropes that have replaced years of almost entirely incident-free soloing.
It doesn't seem possible that unroped downclimbing could really be safer than rappelling. Perhaps the distinction is that the unroped climber attends fully to the task at hand, whereas the rappeller, engaged in an activity that is as unforgiving as soloing, but has become routine and apparently trivial, is more likely to have a momentary lapse of attention.