This reflects something I've been preaching for years, once you can hit a ball 400 feet, additional power has marginal value (i.e. you might get a half dozen extra HRs hit into the wind or pitcher friendly ball parks), they don't give you extra points for hitting a ball 450 feet. Which is something Franco still doesn't get. It's why Rupp turned his season around (takes the ball where it's pitched) and Joseph gets himself out (trying to pull outside pitches and grounding to SS).
Plate discipline, pitch recognition and the bat speed that allows you to wait on pitches has more value, even in terms of ISO, than additional power.
This is the flip side of pitching, once a pitcher throws 92, throwing 95 has less value than command and plus secondary pitches, or why Nola is a much better pitcher than Pivetta and Velasquez.
This is why Klentak is focusing more on "baseball players" than raw skills.
Hoskins hits like the guys on the Nats, he lays off close balls and forces pitchers to throw something he can handle in the K-zone.
While the extra walks helps the OBP, the real key is not to waste those three strikes swinging at the pitcher's pitch. If you only swing at strikes, you have a much higher probability of making solid contact.
I think power hitters have the same problem as powerpitchers - the seduction of the "blast," the joy of blowing a 97 MPH past a hitter for strike three.
This causes players to focus on "peaks" rather than efficiency, but baseball is a game where consistent performance is more valuable than spectacular plays.
Hoskins looks like a guy who'll be a consistent hitter for a decade.