This is fairly common in academia. Instead of having to explain something every single time something common happens, you just throw it on a web page and link that. Reference letters, office hours, and LaTeX formatting are all super common here. I understand why you might respond this way; I view it just as a different kind of https://nohello.net

"Miscommunication" is a very charitable interpretation.

For certain people, this behavior is a pattern. You give them an inch, they take a mile.

I think the point is, that they DO know who they are. They are being specifically approached for some sort of expertise, and being asked to spare their time for the benefit of the person proposing the meeting.

If you ask someone to do you a favour (even if its just to listen to your pitch) then I would say its common decency to not put that person out more than you absolutely have to.