‘Bad’ feedback can actually be good for blogs. It gives you clues as to where you went wrong and from there, how to improve.
“Focus on bad feedback, rectify and improve!”
Perhaps you could also add that people can give suggestions as to how to rectify the problem. Not all bad feedback is actually ‘bad’ as some are actually good feedback in disguise!
So when there is a negative feedback in your Blog next time, face it and solve it! Moderation is not only about removing negative feedback :)