[78124781]

Many codes of conduct and various other speech codes do, in fact, violate freedom of speech and have often been struck down as violations of freedom of expression. Appeals to "courtesy" and "civility" tend to be used selectively. I agree that it would be ideal if people debated courteously, but "civility" is far too often only desired in one direction (and employed as such in practice).

There are plenty of ways for an outnumbered group to still have its voice heard, from speaking at public meetings to writing opinion columns to being active on social media. Or in academia, they can start their own journals, organize their own conferences, etc. Dissenting opinions in court rulings are excellent examples of including the minority opinion as well.

If anything, supporting freedom of speech and expression protects those who are in the minority more than adding more restrictions on speech (since, as other comments have pointed out, who gets to decide what speech to censor? it's those with the power on campus).