I think that would be a great idea only if.... it costs a major amount of karma for each complaint and you can't go negative in karma.
The advantages are :
Newbies can't complain about moderators as they do not yet have karma. Basically give them the message "learn the forum before complaining"
Complainers will run out of karma soon.
People with little karma (who care) may think twice.
I think this is something to think about.
Best regards
Jantje
Ps to stay positive:
[EDIT]
Image is sourced from http://despair.com. For those with a sense of humor and need a laugh; watch the video's http://spin.despair.com/video/