It is the self hosted part that bothers you?
I self host my code. If you can't bother creating an account or sending an email to share your contribution, I guess I'm quite fine not to have it. I'm sure ffmpeg don't need your contribution as well.
I don't get this stance. Sending an email or creating an account is so low effort compared to any meaningful contribution.
The friction is not intentional but I guess it's a feature, it probably filters out some low quality interactions.
Note that ffmpeg has been using mailing lists, they are not migrating away from github. I'll just assume you wrote your comment without going further than your initial gut reaction to the title, which kinda proves my point.