Remembering to look for and ignore folks with that telltale indicator has made the fediverse so much more enjoyable.
Nah, they chose it because the ccTLD along with few others had been free for a long time. I was there when lemmy was just a few months old.
Someone made up these reference about marx/lenin claim and was perfect for wankies to circle jerk and the tankies didn't refute it or went along with it, so it stuck.
Before that the free domains were mostly used for spam/phishing (because it was free and being similar to .mil), some called it machine learning, my links, my library and so on. US military sent lots of emails to this cctld because of unchecked typo.
Except lemmy (& maybe reddit? to detract people from the fediverse), the .ml domain is not considered marxlenin anywhere else.
https://dev.to/bauripalash/lets-get-your-own-free-domain-5f16
https://www.theregister.com/2023/07/18/us_military_mali_email_typos/