How "subtle and insidious" is it really? I'd say it is shifting the blame of personal responsability to a website. Me and some of my friends use(d) 4chan and we never fell into the pipeline. To the contrary there is a strong left-wing camarederie. And I'd wager that we recognize subtle right-wing views more easily. One doesn't learn about these views by looking at a twitter screenshot but by engaging them.

We should stop treating right-wing ideology as a mind-parasite. And if we do it anyways, we should accept that some people want to get "infected".