It can of course be argued that cookies and biscuits are pretty much the same thing. To a Brit, the word biscuit actually means “cookie”, but then it also means “cracker” and also, on occasion, even “biscuit”. Why do they use one word to denote all those different things? Who knows? It’s not like the word cookie is any kind of big secret over here, something we Americans are careful not to say in London for fear those copycat Brits will steal it. They know darned well there’s a separate word for cookie, they’re just too proud to use it. Just like they’ll use rubbish but won’t say “trash” or “garbage”. Why? Because they’re colonial expressions. We dare not speak their names, and if you’re not going to finish that biscuit put it in the rubbish bin, Nigel.
Of course the price they pay for all this hard-nosed elitism is that they have to refer to everything that’s small, round, flat and edible by its brand name, lest they end up slathering brie on an E.L. Fudge. Serves them right if you ask me.