Dude, you’re misunderstanding. No one is saying the ideas can’t be discussed. People are saying he’s irresponsible for giving his platform to these people without doing his due diligence to inform the audience when they lie or say things that just aren’t true. It’s his platform and his responsibility to not send the information out in a vacuum that gives it space to spread without informing people of its (il)legitimacy.
Check out ONRAC for what I’d say is a pretty responsible way to discuss fringe (or just plain wrong) ideas.