The karma system discourages duplication and it is worth its weight in gold just for that. Imagine if the 50 people that agree with a comment felt the need to chime in. Whereas with karma you upvote and are done with it.
To a newbie, karma voting patterns have huge instructional value (at least they did for me)
Why assume that everybody that upvotes now would take the time to "me too"?
If anything what I see again and again is that some comment takes a quick lead in upvotes in a topic and dominates the conversation afterwards, despite being often followed by more interesting comments.
> I'd like to see the karma system dispensed with entirely
Totally agree with that. Comments should be judged on their merits, not the number of points they have gained or lost. Disagreement should be expressed using actual words rather than "thumbs up" or "thumbs down". Removing comment karma would slow people down as they scan comments: rather than just looking for the highest-rated ones, they would have to look at the meaning of all of them. Bitch-slapping commenters with a down-vote doesn't add anything to community or discussion. Clicking the "me too!" upvote button doesn't help that much either.
Keep a flag for "spam", "inappropriate" or "offensive" and leave it at that. People who habitually misuse those buttons should lose the ability to use them at all. People who are constantly (and justifiably) reported using them should have their account limited in some way, maybe limiting the frequency or number of comments they can make.
(I mean comment karma, specifically, not submission karma.)
