>>djtrip+(OP)
Seems like a non problem. If it's a dull comment or just inane it'll get downvoted out of existence. If the bot actually produces something interesting about the topic, what's the problem?
>>bragr+C4
Because this places the burden on users to sort it out. And you're ignoring a third category of comments: bad ones that are glib enough to garner upvotes.