And no, I'm not "maintaining some fork"--there's no way to submit patches on GitHub, and the only way to get changes in for most projects hosted there is to throw up a copy of your work as a remote for someone to pull from. My disdain for this workflow is already well-documented.
Pointing it out doesn't mean it was "surprising". Just that it happened -- and as such, it could be a possible conflict of interest.
"Contributor to project X trashes competitive project Y" is a different situation than "Totally unaffiliated with X and Y person, trashes Y".
Perhaps there was bad blood between the two projects, a backstory with interacting with them, etc -- in which case it would be good to know, that's why I asked.
Now, if there were more technical arguments it wouldn't matter -- they could be evaluated regardless of who tells them --, but your comment was mostly summed to: "they are inferior quality" and "they only succeeded because they use vim's name directly", which doesn't leave much to evaluate.