I don't want to re-dig this discussion.
People who don't use "#pragma once", have directly cited this exact reason as the sole reason that makes any sense, by which they were opposed to adopting a feature that they are not forced to use, but others could. And the problem was because others could.
There's no arguing this!
We can agree to disagree.

-----Original Message-----
From: Ville Voutilainen <ville.voutilainen_at_gmail.com>
Sent: Monday, September 23, 2024 3:22 PM
To: std-proposals_at_[hidden]rg
Cc: Tiago Freire <tmiguelf_at_[hidden]>
Subject: Re: [std-proposals] Revising #pragma once

On Mon, 23 Sept 2024 at 15:21, Tiago Freire via Std-Proposals <std-proposals_at_lists.isocpp.org> wrote:
>
> Here’s the summary of the discussion for those who missed it.
> The reason why people in the camp of “no to #pragma once”, has little
> to do with the technical details

So, at this point this "summary of the discussion" becomes a distorted opinion piece..

> They want to be able to bully 3rd party developers

..and this puts icing on that cake.

It has everything to do with technical details. There's no bullying of any kind. At least not in that direction. The same cannot necessarily be said about the other direction and its message "you must accept this proposal even though you have practical uses broken by it, just fix those uses, it's easy".