Even better would be if there were user-configurable "lists", whereby you could decide upfront what you want / don't want to see (like many sites do right now with NSFW content) - the default filter would be very "protective" (no porn, no violence, no gore, no hate speech) but users could turn off any or all of these "filters". The next step is the addition of user-curated "lists" / "filters" (e.g. "no democrats", "no republicans", "no vegans", "no dog lovers", ...).
The only way to actually change someone is conversation.
Only those who don't want honest change fight to prevent actual conversation from happening.