This is quintessence of a typical discussion on the Internet. Context matters and it's expensive to gather appropriate context. Usually it's not as simple to explain as in this case.

"I don't have to read further because I know for a fact that <this bit> is bullshit". It's a fair heuristic. It's just that it is so difficult to have a deeper meaningful discussion without some trust established first (so that you know you're not wasting your time).