I don't think that will be a problem. We're now paying graphic graders for the express purpose of giving sig makers feedback and advice and I think for the most part, graphic guys WANT to improve a lot more so than say a writer. You know what I mean? I think people care more if their sig sucks more so than they would if their media spot did
In any case, docking people when they are trying is doing nothing aside from discouraging people. Hell, my first point task in the league was a graphic and I got a 5 on it. Guess what I haven't posted since? I did want to keep working at it, but at the time I wasn't willing to sacrifice TPE for it and so I never returned.
I did the same thing back in the day, never did one after that.