Because insuring free speech includes everyone and the most strident assholes believe themselves to have the right to speak first and as loudly as possible.
It doesn’t mean we don’t discount their bullshit and laugh at them, it just means they are the loudest and quickest.
Just to be clear, if they do somehow bring up a valid point, it is not dismissed out of hand like the obvious bullshit is.
I think that the neurotypicals have ability to make these things onto “habits” that then happen automatically for them.
As a person that has to remember to every time, and decide everything I do, from what time I get up, to when I drink (and what) to when I shower or even brush my teeth, it is exhausting just maintaining daily hygiene and while I fully understand why I need to do all those things and WANT to do them to maintain myself, none of it comes without considerable forethought and considered decision making.
Frankly it can be exhausting just to exist, let completely alone, progress.