It's not rust per se. It's a human trait. People make uneducated assumptions about the topics all of the time, and it's completely normal since your have to bootstrap yourself somehow to be able to grow further. It's impossible to know everything. And it's also a difficult situation because you do have to arrive to some conclusion. I do think, though, that in this particular case, assumptions made are a little bit all over the place and the tone is overconfident.