Because those are decisions we've collectively decided we should support people's right to make. There's not much support for the right to decide to be an asshole.

but there is - that's what the right to free speech is. As the old saying goes, popular speech doesn't need to be protected. Being "an asshole" is not an objective measure, so you need to draw a line in the sand between legal and illegal speech. Free speech is the line that says "you can say anything" except for a few specific cases that are liable to put people in direct fear for their lives/wellbeing.

Not sure I agree. In the history of humanity, religion has done much more damage than e.g. white nationalism.