That is a very important statistic, but then again, we are underwater.
I personally believe that the simple failure (refusal) to carry some independent and meaningful redundancy (i.e., a pony bottle) must make up a good portion of the 41%; how could it not? I wonder what percentage of the 41% is just composed of people too distracted to look at a freaking gage on a reasonably frequent basis.
So the pony is probably more of an attempt to address the symptoms rather than the cause of the problem; in most situations.
I kinda like the two-fold approach: All divers should know just enough to make sure they almost never need a pony bottle..
And of course, being strong enough to kick a pair of fins for 60 seconds isn't a bad idea either.