The Brewers use a lot of situational hitting -- bunting, contact plays, etc. Based on my flawed anecdotal observations, even Contreras and Hoskins have been looking for RBI by going the other way, even if it means softer contact.
The elevation doesn't bother me as much as their collective passivity (5th lowest Zone Swing %, 3rd lowest Swing%), which routinely puts them in two-strike counts. They are 5th in the league in OBA in 2-strike counts, which mitigates the passivity slightly, but being so selective, they are struggling to do damage on good pitches, ranking dead-last in barrel rate, and 3rd lowest in average exit velocity.
With that said, 2-strike counts are often deep counts, increasing the likelihood of a walk. Also, their lineup is littered with guys whose games are built on making contact and running. Perhaps the organization and the dugout staff are simply coaching players to play to their individual strengths rather than trying to elevate. If that is accurate, the low launch-angles could be a criticism better aimed at roster construction.
To be fair, though, I'm a launch-angle denier. I'm a big believer in hitting the ball hard, regardless of launch angle. Some players' swings/strengths/weaknesses are better served by learning to hit a variety of pitches in a variety of locations and counts, rather than gearing their swings for launch angle.