I really don't see where you're getting that from. How on earth does it "rewrite your code to mean something other than what you intended it to mean?" I explicitly included the "markdown" identifier. What on earth could I have meant otherwise?

How is:

   import markdown from 'markdown-in-js';

   const MyMarkdown = markdown`#Headline`;

any less clear than:

   import markdown from 'markdown-function-tool';

   const MyMarkdown = markdown('#Headline');

It's totally explicit and actually allows compile-time validation. I really don't understand your objection.

This will not be "unreadable in 6 months" any more than JSX or GraphQL are. Since I have plenty of projects that are over 6 months old using those techniques, I'm quite confident they work fine. It's not like there's any magic or implicit references going on.