I would say yes if you qualified that to say "strikeouts looking". If most of the increase in strikeouts were swinging strikes, I don't think it invalidates the theory. Even then, I think it's more complex than that. Guys take more pitches in general now than they did 20 years ago. Perhaps emboldened by a sense of calm with two strikes, guys take closer pitches in those counts than they did 20 years ago. If the umpires change the implicit rules of the game, players will adapt. That's what I see. You watch the Red Sox and Yankees play and the players are shocked to be called out on strikes. They walk back to the dugout shaking their heads and sayings stuff under their breath, the gist of which is, "You're not supposed to do that!"