Why even bother trying to explain something to others if free will is an illusion? What are you relying on to persuade them if they don't have a mind capable of understanding you?
Indeed. Even if you don't believe in it at a philosophical level, you don't exactly have any choice in the matter. We all behave as if we have free will -- the only alternative would be to just stop doing anything (e.g. being catatonic).
I personally believe in free will, but persuasion and learning can still exist even if free will doesn't. It could be argued that people's deterministic reactions led to them reading something someone else posted and that leads to their mind changing. Memes and movements would exist even without free will. It happens in experiments on simple organisms that arguably lack free will (those with very narrow and predictable behaviors).
Some of HN understands hard determinism and once in awhile I see an interesting post. Otherwise it's just a comment triggered from reading the article. I enjoy it.