Since the temperature on this thread is already high I'll keep this personal i.e. just about me (PA28 and C172)
Here is my ponderment.
We all agree that pre-flight checks are an essential part of keeping alive, the discussion is about when, where and how quick. As an inexperienced PPL of 250 hours I can accept the speed thing; as you become more experienced you probably can check things more quickly and no less thoruoghly than when you first started. But I do puzzle about doing the checks whilst taxiing, unless what we mean is ....
I have had three instances of checks that resulted in me not flying and all discovered before taxiing. Maybe they saved my life (and my passenger's), perhaps all would have been well. But I didn't hold anyone up, I wasn't moving, I wasn't in the way of anyone else and there was no danger to any other aircraft.
But, in fact aren't we all doing the pre-flight checks the entire pre-flight time? I do all the checks I can before taxiing, then more whilst taxiing, then the power checks (again), and so on. And then I guess the principles are the same for every aircraft with differences by type.
I don't know have any experience about the type in the post that kicked-off this thread, but I would have thought that checking for water in the tanks would be a basic check for anyone. Or is there some great technology that prevents condensation in tanks these days in light aircraft? No judgement or pretensions to expertise intended.