The clear misinterpretation happens when I said 'beginners eyes' to assume that I'm some sort of 'beginner', when in fact as a maintainer I keep hearing the opinion of students and newcomers making this comparison and they use their preferred way to contribute (Github being mentioned often) when joining a project. Therefore, you giving a very naïve assumption that I somehow wanted to force everyone to '...register on some random web service' when I clearly said that beginners should start with a similar open-source project using similar tools like Gerrit, GitHub before trying something harder.
Yes, I have confidence that everyone knows how to reply to an email. But in comparison to tools like Gerrit or Github, I won't expect many non-commercial contributors to stay for long if the review process was via mailing lists, unless they are paid to work daily on the project, which is why I recommended beginners other OS projects that have a similar review process before going onto looking at the Linux kernel.