Like the web itself, commercial companies will eventually come around. It can be the "new new" content marketing, since it's a small step from source-discovery to company-brand-discovery. Code becomes a proxy for author-reader connection, like prose.
We can culturally transform "view source" into a reputation metric that impacts visibility and revenue.
Look at the code snippets in the recent Bloomberg article, "What is Code", http://www.bloomberg.com/graphics/2015-paul-ford-what-is-cod.... Imagine a weekly NY Times list of Top 10 New Code, or Genius.com annotations, or CC-BY code comments which appear in search engine results, etc.
Society will increasingly care about coding, as writing code|prose influences thought, and more people will seek to understand the tools that make us as we make them.
I think many people would gladly opt-in to adopt the standard you proposed, but perhaps commercial projects won't have the incentives to do so.