Is it necessary to rate negative your respondents?

Tweet

Many users complain about the negative rating that ruins their reputation. Is it necessary to rate our respondents?do you rate every responses to your discussion? I don't feel the necessity of rating each responses in my discussions. I just read and leave it that way. But if i feel a response is brilliant, i do + rate it. And i never rate negative to responses against me. I think everybody should be the same way.