To quote myself:
frankly I think binning the trolls and leaving the backslapping kudos is a bit... I dunno. Disable comments best way full stop.And I stand by this. Let's be clear I'm not suggesting the blogger was doing that, but I know people do.
If you want a "critical" discussion on a topic are comments that say "Great post! Totally agree!" any more or less valuable than posts that say "What a load of shit, you're a moron"?
Obviously there is a HUGE variety of opinions between those two "binaries" and that's where your critical discussion comes from.
But if you bin all the flat out trolling and keep the empty meaningless platitudes (aka backslapping kudos) there's no balance and it invites more trolling because it looks like you're favouring positive commentary.
So, either delete the kudos too or keep the trolls and let them revel in their glory/be seen for the idiots that they are.
Or, if you post something controversial, just disable the comments. Your blog is for expressing your opinion, it doesn't always have to be about discussion and criticism.