Why is that uncivil? A lot of online discussion seems to be exactly this.

I would imagine the comment was more to convey "don't hurt my feelings" than to encourage civility, which is a more difficult concept. For ideologues, good means rational means civil means moral means <insert political ideology>.

Once all words boil down to <ideology> or <not ideology>, a person can't express or precisely articulate ideas, which manifests in incoherent language.

It's especially funny considering the argument of the person calling for me to censor my thoughts is the same person crying that conservatives are forced to censor their thoughts.