Wasn't SD saying we use 25% more than historical, as opposed to industry average? Industry average is easy to understand: we don't reward flying sick.
As for the presumed spike in historical usage, I would attribute it to a convergence of factors, not least of which is 117. Add the fact that people are using SB/SWF to fly up to new 117 limits, and you end up with a bunch of tired guys, that don't resist well to getting sick.
The "data" we're being provided isn't any more substantiated than Carl's allegations about sailingfun. File it under "self-serving rumor".