Seems to me we're just seeing a league wide movement towards a lot of pretty good home run seasons*** without other achievements to note---except smashing strikeout records. To me, that suggests it quite possible its coming from a change in hitting philosophy and technological change is causing fly balls to become home runs.
Back in the verified steroid era, they hit more doubles, they hit more triples, they struck out much less, they had much better averages, etc.
***In other words, and someone can do more crunching numbers and prove me wrong or I can try when I have more time, but seems like we're having more pretty good seasons but less of a dropoff to the "rest" of the league and less of a clumping of a group of mega-mashers like was seen in the steroid era.
Does that make sense?