Sure blacklist was already an English word, but it's not necessarily _common_, and the distinction between blacklist and whitelist is kinda arbitrary. If you'd like to explain Why the word means what it does I'd love to hear it
Allowlist and denylist are clearer, in that the meaning is in more clear alignment with the words it's made up of.
The old terms just make more sense to those who are old enough to be used to it.
As for whitelist and blacklist, I don't remember having any difficulties with them. Maybe on the first encounter, but that's it.