I think that the training emphasis should depend heavily on which age group the kids are in. If you have U14s or up (okay, maybe U15s) dribbling in circles working on "technique" at training sessions, that is a waste of time. It looks intense and makes it easy for poor coaches to pretend to be good coaches, but the ECNL coach is spot on--technique should be developed on their own. But your kid can't do possession drills or work on positioning and movement on his own.
If these are younger kids, then it probably would be a good idea for the ECNL coach to re-emphasize shoring up their technical skills and spend a few minutes at each practice checking their progress. If they're older, then he should look for better, more motivated players

.
Regarding the "seriousness" of the practice, that's not really dependent on league or what is being covered during the training session. That's down to the tone the coach sets.