Not a huge surprise there is a large anti-capitalist faction on lemmy, so this isn’t terribly surprising.
I’m no meta apologist, they’ve done enough to warrant skepticism. The reality is they can harvest the data even if you defederate their main instance, by setting up shadow instances or just scraping other instances, so that argument doesn’t really hold water for defederation. The bigger one is content vs spam coming from their instances and possible EEE measures, but immediate defederation only serves to keep them siloed off and does not let them function as an offramp to better instances for regular users.
Could still get hacked, but the point stands that is an extra level of verification.