Your claim isn’t true and your link doesn’t say that. Question of accessibility and what is forbidden are two totally dfferent things.
Plus around millions sites, including practically every WordPress installations, proves your wrong.
And there is more 
Do you know what googlebot does with JS AND non-js content? It sometimes index both, but is using JS-version and serving that content as search result.
Google is just warning that users who can’t see JavaScript can’t get that content and that is not nice. But it has never punished because of that.
So, this topic is not about SEO. It is stronly about basics.