One thing is certain when you discuss Linux in public: someone will chide you for not using the “proper” term, whether that’s GNU/Linux or something else. I don’t know the exact motivations of each person, but they’re very irritating.
Most people mean the Linux ecosystem when they say Linux. That’s a normal evolution of language: a word for something specific becomes a more general term. “Linux” is easy to say and easy to remember, so it became the standard term.
Fighting against a logical and useful evolution of language is always a losing battle. One can drill down with qualifiers (Linux kernel, Linux boot loader, Linux DE, etc) if they’re one of the tiny minority who mean the kernel when they say Linux.
The rest of us will proceed happily along meaning the ecosystem of applications, tools, and people when we say Linux.