We do comment cards for low scores AND for high scores!
And, trying to do cards for each entry just is not realistic. You do not have 30 minutes.
You also have to try a bite, wipe your hands, records your comments (usually with a dull pencil), then try the next piece and repeat process. Heck, I have been to comps where the judges table are like little card tables and to have 6 people sitting there; need some elbow room!
Some comps get behind in bringing the boxes to the tables, so you are really crunched for time.
The last comp we judged was Smokin' On The Bay last year. I know I filled out 15-18 comment cards. Some were for low scores, and some for really high scores.
If there was more time between turn ins, that should give more time for comments.
As for me now being a competitor, I want comment cards!
I also believe there is a lot of stuff that could and should be done by KCBS and the reps to promote the comment cards. But, there is not really much said.