Everyone is welcome to attack the consensus. You just need to be backed up by very strong evidence. That's all.
The reason people today dismiss "dissidents" is not out of a politically correctness deciding what is acceptable and what is not, but because most dissidents are nothing more than populists, getting known out of a "buzz" and not out of any actual proof of anything. You might call them "scientific dissidents" but they're nothing more than scammers or sect gurus, as the proper scientists that actually rely on proof do not need to go on TV shows or social media to convince the crowd. There are still some bad behaviour inside science, but most of those are never reaching the public. As long as it doesn't reach a TV set, it is basically invisible, and the ones that reach them are rarely worth considering.