I don't agree either.
Yes, you prepare to launch your swing on every pitch ... and yes, failure to adequately prepare leaves many young developing hitters unprepared to launch their swing.
For sure. I see it less now in 14U TB with most players having experience at a high level of play, but at younger ages, it was pretty common to see players having trouble adapting to faster pitching because their intent was flawed and preparation wasn't happening early enough. IMO, a big part of intent is having a "predator" attitude when you step into the box.