Porn offends some people as well (and is not meant to be viewed in certain social scenarios, of course). Reddit has a "safe for work" and "not safe for work" category, and as far as I'm concerned this dividing line is probably better than the no-nudity-period type policies of Facebook (which leads to dramas over non-pornographic nudity, eg breastfeeding photos, a famous Vietnam photo, etc.). It seems like cute pictures and jokes drive more growth to me at first glance then porn, anyways.
Managing "toxic behavior" is a lot trickier, from what I see -- over-heavy moderation also can lead to issues. But "growth at all costs" social media, without checks, leads to factors such as bullying, abuse, and harassment listed as negatives in articles on your growth prospects.
Porn and white supremacy constituencies are similar in the context of a VC backed company whose trajectory is tied to an equity event. That is that they drive lots of engagement and probably more time on site.
Reading the article, the author’s point was that pursuit of growth at all costs creates bad situations like echo chambers for racists.
Other sites like Stackoverflow avoiding this sort of situation by being intelligent and strategic about pursuing growth.