Given previous attempts to cull inactive members from privileged groups, I think the level of sneakiness was appropriate.

Previous attempts?

I've been mostly inactive as a janitor for well over a year. A simple /msg noting a desire to cull the list, and I would happily have relinquished. (And a /msg after I'd been removed from the list would have saved me some confusion if I did see something that needed janitoring, felt so inclined, and then found that I couldn't any more.)

The way this was done feels like one of those student government takeovers by the cabal who've figured out how to use Roberts Rules of Order to exclude everyone else. Being a janitor requires hanging around in the editors' wiki? I rarely did that back when I was doing a lot of janitoring.

To my mind, you'd have been better off saying publicly that you were going to cull the list, and that decisions would be arbitrary.