There is such a long history of using humor to affect change and discuss extremely serious matters. Legally it's protected speech because of it's importance.
The main purpose of sarcasm is not humor, it's to use irony as a form of contempt. To the extent that humor is involved it's usually done so as a form of mockery.
I agree that satire and parody have a valuable place in discourse.
But I believe there are some subject matters including sexual assault and more specifically pedophilia that are pretty much never in good taste or useful to parody. Apparently this position is somewhat outspoken here.
Swift's Modest Proposal mentions eating babies which is very obviously an extreme behavior that is not tolerated by anyone anywhere, which is a distinct contrast to sexual assault which has victims in the millions if not billions.
Also just to note that the comment I replied to is now dead and flagged, so I guess I'm not the only one with these opinions.