Couple fangraphs articles I've read now. Here's an excerpt

You want to talk “harvesting,” this is your guy. He has totally sold out his liner and grounder authority, focusing on more of an uppercut swing to hit the baseball for distance. Very few hitters hit the ball harder as the launch angle increases; however, Votto’s average fly-ball velocity (92.3 mph) exceeds his average liner velocity (90.1 mph), which exceeds his average grounder velocity (79.4 mph). The vast majority of hitters hit their liners hardest of all. Most of the players with such a profile are nearing the end of their productive phase.

Votto’s average overall velocity of 87.3 mph isn’t eye-catching at all; from 2008 to -13, his overall average was over a full STD above league average, but by last season it had settled into the average range. His liner rate has plunged this year. He has simply been no longer content to be the perfect hitter and instead focus on dropping more homers over the short pull-side porch. Hank Aaron, 1971, all over again.