Responses

I think it's probably bc the word has evolved to encompassing agnosticism now.
Ofc, strictly speaking that's not what atheism is, but words evolve with time. It's a lot easier for people to recognize atheism over agnosticism.
Kind of like how the word "literally" has evolved to meaning "figuratively" (as paradoxical as it may be. Now people use the word literally in sentences that are meant to be conveyed figuratively.
I feel like alot of people mix up Atheism alot. Atheism is when you believe a God doesn't exist. If you know they exist and you don't care is different. If you know they exist and you hate them, it's also different but it's not Atheism because you're either fooling yourself with the irony or just ignorant