What is happening especially now is precisely that, this whole 'misinformation' drive is to encourage the dismissal of critical opinion (on more and more topics it seems). This is a bad road to go down.
And you make a good example of the overall point: there should not be this 'mainstream' vs 'not-mainstream' and we just pick a side. We should all be mature enough not to fall for that silly manipulation and instead try to fully inform ourselves from a range of sources and challenge ourselves.