Torts seems to be making two points here:
- One, it's not the "right way to play" and thus "it shouldn't be in the game."
- Two, it's not your best option versus a pass, a wraparound tuck, opposite corner wrist shot, or any number of other options with teammates in various positions in front of the net to accept a pass/defenders covering those guys.
Those are two distinct reasons. I can get behind the second, but don't have a lot of time for the first reason to dissuade your players from doing it.
I would have no problem telling someone who keeps attempting the Michigan, and failing, to stop doing it and attempt more high-percentage options instead. Yet in the case of someone who can pull it off at game speed, it should be in that player's toolbox. You'll keep opponents honest, if you periodically use it successfully, when everyone is taking away the low shot/pass and there is a clear opening for someone who has practiced it extensively.
Score any way you can. A goal is a goal, and I don't much care how it makes coaches or opposing players feel. Maybe expect extra attention from opponents the rest of the game, though.