There's a hell of a lot of difference between presenting an opinion and presenting something as fact, without backing it up. "citation needed" is an apt respon

There's a hell of a lot of difference between presenting an opinion and presenting something as fact, without backing it up. "citation needed" is an apt response if something is presented as fact, without backing it up it's not relevant for arguments, which are clearly presented as opinion. It doesn't really matter how outlandish an opinion is, but if you make assertions and present them as fact, then you better be prepared to back them up with evidence.