In light piston planes (as in jets) glass cockpits are great. I could not believe it when I had terrain, airspace, and TCAS on my screen the first time I flew on a C-172 with the G-1000. I would never recommend substituting training in conventional instruments, but they can compliment IFR training to some degree.
Maybe the numbers are higher because of the popularity of these aircraft in flight training? Many schools have switched completely to glass.
I agree with the V-Tail analogy, especially now that some are even equipped with TKS anti-ice systems. Grab a nicely equipped Cirrus and you might forget you are in a piston single. AP, FD, XM WX, Radar, TCAS, GPWS, EFIS, Anti-Ice, etc. Leave it up to marketing to turn the requirement of a parachute attached to your aircraft as added security for you.
If used correctly (like everything else) glass in light pistons is a great tool.
rcl