@velartrill I think this is largely due to two factors, the popularity of post-modernism (the ideology, not the alias for "stuff i don't like") and the cult/group mentality enabled by social media.
Post-modernism as an epistemological relativistic ideology (i.e. subjective idealism) states that all interpretations of reality are equally valid and that empirical evidence has little to no value. When this is put together with the ability of social media to dehumanize others and create mobs we have the quick and strong rise of the "narrative" that manages to acquire enough acceptance first. From there anyone that deviates from this line of though is quickly cut off, or "cancelled", by the mob.
Of course the fact that the fact that people in general have poor critical capacity, due to the deficient education system in most countries, doesn't help much either.
Why and how post-modernism managed to gain so much acceptance is still a puzzle to me.
The fact that dumb 13 year old kids from /b/ "warned" me about this as early as 2012 makes me feel weird.
gamers rise up i guess?
@velartrill Yet another hypothesis is the social grooming one. You see, in primate societies grooming is very important. It alleviates stress and strengthens bonds.
There have been analogues traced with human societies in which gossip takes the role of grooming.
But you have to gossip about something and with the quick information flow of social media that something comes and goes way too fast. Sometimes leaving people without something to gossip about.
With post-modernism you can make something up to gossip about.
The grooming hypothesis also helps explain the formation of mobs but it doesn't say anything about why the left and queer movements specifically got caught on it.