How do you deal with bad reviews?

Perhaps your critiques have reason(s) for giving you a bad review.  In this case, examine their comments: are there any truths to it?  Most often bad reviews contain, at least, one recommendation.  Work on it, then, wherever applicable.  

On the other hand, if the problem is not on your side, consider brushing off the bad review.  It's your work anyway.  Besides, there are people who could not see any good from someone else's work.