I agree with the overall message here; there's definitely better words for customisation of a Window Manager/Desktop Environment.
I can't agree that everyone using that term is racist though. I doubt that everyone who uses it is doing so to discriminate or abuse another race. As proven by this thread, the history of that word isn't exactly common knowledge in the spaces people are using it.
"bigot" might be a better term to describe people that know the history of the word and actively refuse to change their ways. It feels like throwing "racist" on here where it doesn't exactly apply sort of dampens the impact of the word. But that's just me.