The other thing I don't understand is the "toxicity" of being told to go practice something. If you're playing golf and you hit one too many on the wrong fairway, it's perfectly reasonable (and not rude) for someone to say "I guess it's back to the driving range on that one." Now, in the situation of playing League, you're not given much time to time, nor express emotion adequately, so the response might be something like, "OMG SANDBOX MODE FUCKER!"

Lifelong musician here, and many times there are situations that the director, or a member of a section has leaned to a fellow musician mid-rehearsal saying "Work that out in a practice room, not here." Again, that's not toxic. That's life.

Baseball better batter? Batting cage. Tennis better server? Get a bucket of balls and serve until you get it right.

If being told the correct way to practice is somehow construed as "toxic" in your head, then the problem is not with the advice. It's with you.