I distinctly remember when our relationship started getting serious my girl told me, with a very adamant tone, if I ever did a public proposal she'd leave me on the spot. We'd just been to an anime convention and some dude at a panel did this whole rigmarole to propose to his girl up on stage in front of everyone, and it was pretty cringe so I figured I understood enough why she was so against it. Seeing some of these videos I understand even more now why she had that "out for blood" tone in her voice at the thought of a big public proposal.
Also the reasoning she gave me was almost 1-for-1 what Pippa said.
So yeah I think I'm fully on team "don't make a public proposal it's a shitty thing to do."