My memory is hazy at this point, but my recollection of the original grievance was that there was a (funded?) Palantir employee on the Rust team at the same time that they decided to put out a message in support of racial justice. The former certainly doesn't help the message of the latter, and people were (in my book, understandably) upset at the dichotomy.
My own work is partially funded with defense money, because the DoD funds everything. I'm not so happy with that, but I do think that working at Palantir requires several additional steps of introspective moral failure than merely receiving DoD money does.
That's a highly partisan opinion.
C++ is used to write literal missiles that kill civilians in the middle east, but you don't see the leaders of the C++ community who work for big surveillance / big military / big tech also LARP as American communists on Twitter while working for CIA operations (although, if I have understood it correctly, black lives do matter to the CIA, it's the brown ones they have issues with).
I;m sure some will read this as me supporting Palantir, because that's how the Internet works, but I don't and find them unpalatable.
The same goes for travel costs. It seems a delicate issue: do you fund people who are deeply involved in the project and have shown a continued effort, or new members who might drop next week? To the author, the answer seems so obvious, to me it isn't.