Is it my responsibility as a judge to make a team better at cooking BBQ? Of course not.
If I judge a teams entry below average, is it my responsibility to articulate to them why...of course it is.
Until a judge has that mentality, making comment cards mandatory or not is pointless.
I am sorry I don't know how to tell you how to get a judge to that point, for me it was many years and competitions, both judging and cooking.
Certified Master Judge #5382
What is best in life? "To crush your BBQ opponents, to see them driven before you, and to hear the lamentations of their women."