What you're seeing me and 'woodruffw implying is that modern formats are (deliberately) trivial to parse. OpenPGP is not. That is a security design feature that OpenPGP lacks, and it's a big one, because it's caused multiple issues already.
Yes, I understand and never said I disagree with that :) I'm just trying to provide some nuance and background about the specific issue discussed in this submission, as IMHO I think it's more interesting than making the same high-level points about OpenPGP over and over in every thread related to it (no offense meant, of course).