Yes and no. Schwarber is a slow left handed hitter with pull heavy tendencies, so you don't expect him to run a league average BABIP(especially since a decent number of hits should go over the fence anyway). He's also having trouble hitting the ball as hard as he was at the very start of the year: As far as I can see, Schwarber is simply not punishing balls in the zone. He's being as selective as he always has and there hasn't been a drastic change in where pitchers are working him, but his exit velocity on pitches in the zone has gone down. Here's 2015 on the left and 2017 on the right. To me that spells a mechanical problem, compounded by pitchers doubling down on what's working so far. Sending Schwarber down doesn't fix anything, and since once he corrects that he'll be one of the best hitters on the team again there's plenty to be gained by letting him work through it. Considering the alternatives(Jay, Almora, Happ) are all struggling as well, there's no sense in demoting Schwarber(who given his insane work ethic doesn't need a wake up call or kick in the butt) to give the MLB at bats to someone else either.