Givewell, being EAish, is generally staffed by people steeped in ratadj and/or nerd culture, so that seeming like a natural way of describing it to them seems unsurprising.
I mean, I do see your point, and "getting grumpy about such things" is very definitely not an experience I'm personally unfamiliar with, but in context I can't quite bring myself to be annoyed about this specific instance :D
Too used to kicking around with people where it's a basically standard term (not always one used *positively* depending on which group of people, but I forgot it's not always clear).
Genuinely nice to know EA circles are involving/including people who aren't already sufficiently steeped in the origin/history/context/whatever of the movement to find jargon like 'ratadj' as obvious as I thought it was when I originally typed it.
(and it was jargon and I've just edited this comment because my original phrasing almost certainly read as condescending in a way that was absolutely not why I was meaning to say; mea culpa and my apologies to anybody who read the first version)
This does quite seriously strike me as an excellent sign for its sustainability and while, yes, EA has a whole buuunch of weirdness to/around it, I'm unconvinced you could've got a first generation of something like EA without being tolerant of the people who brought the weirdness, so:
Cool!