[late2part]

I think the reason so many people feel that it's important to allow dissenting and objectionable speech is that the perception of 'harmful' speech is mostly subjective.

Relegating that permissiveness to a particular entity allows that subjectivity to be enforced in perverse ways.

Many people feel it is better to tolerate the objectionable and hurtful speech than to allow a 3rd party to use subjective judgment to censor.