This is an interesting subject. We do also have a lot of users who are very direct and not that helpful in their criticisms.
We deal with that with civil responses. In this case, I would not remove their posts but rather respond something like “sorry to hear you had issues with this update, could you give more details about the problem you’ve encountered?”
When you have an unhappy customer, and they care enough to share it with you, the best response it to try to find out what the problem is. If they feel shut down by you removing their posts, they will likely grow even more dissatisfied with your services.