<title> exists to be human readable.

The text within <title> exists to be human readable, but the tag itself exists so that the browser application knows what to put in the title bar.

Uhh ask any non-tech person to write a markdown file. This simply is not true.

Write, sure. But I meant read.

A header 2 tag (h2) in HTML requires no more training than a header 2 tag (##) in Markdown.

I did mention that that was one of the more bilaterally semantic parts of the language, alongside emphasis and strong tags. But I still think the ## is easier for a regular user to understand.