Originally Posted by
Baby Puke
Still very common among non-professional track riders in Japan, home court advantage I guess. I like square taper. It lasts forever. Modern solutions are far more fragile. I've been using the same BB for over 10 years now, and it's not quitting anytime soon.
Edit: Carleton is right, non-square taper BB's are probably stiffer. But how strong are you? Can you flex one of these? I sure can't.
I honestly think it's for the same reasons that loose and caged-ball bearings are rare on wheel hubs: Maintenance.
Setting (and resetting) the tension and cleaning are a pleasure for some people and a P.I.T.A. for others. Properly cleaned, oiled, and tensioned loose ball bearings are a joy to experience. But, they usually don't stay like that for long. And in my experience, most riders/racers don't nerd-out on bike maintenance.
Sealed bearings aren't buttery smooth, but they are smooth enough...especially when they don't require cleaning or a special tool to tension.
EDIT:
Yes, I imagine that it comes easy for a lot of folks, but a lot of people either don't know how to or don't like to do it. Removing cranks and bottom bracket, cleaning all of the dirty muck, de-greasing everything, re-greasing and packing, and reinstalling is a fair amount of work.