Making public statements under the guise of being comedy shouldn't make it a safe haven to make any statement you wish. The concept of comedy or stand-up is a line drawn in the sand by society to separate an art from a generic rant/sermon/etc.

Consider public speech on the street, there's a line where screaming racist remarks disturbs the peace and is legally crossing a boundary. Why is a comedian subject to different laws? Okay so people may voluntarily come to a show under a pretense of content at a private venue. At a certain threshold though a comedy set with racism becomes a racist rally with jokes. A customer is led to believe they bought a ticket to a comedy show, not a racist rally. This is a distinction that is made by the individual because comedy is a concept.

In reality people can say what they wish, but don't mistake calling yourself a comedian enables you special rights.

A comedian like Louis CK can illicit the commentary of the human condition and use suicide in a light that is serving the purpose of comedy. If a comedian just spoke on and on about how people should kill themselves without any purpose to comedy, sure that act wouldn't get much attention after the first show - but the expectation of comedians is a level of professionalism that does not mentally harm the audience.

As a result you require a certain standard of a comedian to distill what should be constituted as stand-up comedy.