I will be succinct.
First, I think you don’t have a thick skin as you claim.
Second, people tend to focus on the negative feedback
Third, people who will expend the energy to type something, which takes energy and time, need to have a motivation. People tend to feel motivated to speak out about things that upset or are negative to them.
Fourth and last. Maybe start listening to what people say? Some might be mistaken in their opininions, but some have a fair point. As humans we can err and its our responsibility as citizens of the world to make the best decisions given the information and opinions we are exposed to.