I'm honestly not sure it's even vindictive. Maybe in some cases, it's a big complicated issue.
We get such different news in the age of algorithms, they may not even see it as vindictive. I think it's easy to pull back from a group that paints your identity as a villain, and I think that's likely some of it.
I think it's too complex to attribute to one thing, I think you're right that the alt right social media pipeline is real and an issue.
I'm just saying I understand not identifying with a group who trash an identity a person belongs to. They just disengage. Nobody likes being put into a box that paints them as a villain.
Just my opinion of course, the left (as a social group) can examine the current discourse and try to adjust, maybe like framing it as a class struggle or a liberty struggle, or continue being divisive and risk being overridden.
Or discourse like that could be why young men are choosing the right.
Why I'm here (first comment yay)
Mainstream tech adoption needs a neat clean wrapper imo. I think that's the biggest missing piece to fediverse, people want pretty, simple, plug and play.
If a wrapper like that could be put on top of/combined with all the good qualities that the fediverse offers, I think it would create optimal conditions for slow adoption.