Demographic and generational shifts are clearly part of it as well, but the numbers are quite sudden which indicate a more immediate cause, in my opinion.

I think it is foolish to dismiss any one particular contributing factor, particularly for ideological reasons. Reality is more interesting when one is able, as best one can, to set aside ones own ideology when observing.

I'm not sure why you'd expect an organization like ESPN to modulate their content in sync with generational shifts. Most organizations try to put off such shifts until the transformation must obviously occur and then rapidly play 'catch up' while trying to innovate for the audience they're chasing. If ESPN is able slowly and accurately follow along with cultural shifts, then they've got some exceptionally brilliant people driving there.