There's a lot of reasons that doing that can be better than trying to make a play at the line, but primarily it's because a turnover at the blueline is already a very bad thing before factoring in our abysmal transition D defense.
That said, players can and do ignore practice instructions in game situations all the time. He's not on the bench with a 360 controller or something.
A better criticism is the team has only a handful of extremely basic set plays in the offensive zone once the zone is gained, they're all easily countered, and most of them aren't good uses of personnel. I call it 90s offense somewhat in jest, but not really. It's sort of amazing they score as much as they do.