But their pushback is for pragmatic reasons, not because they don't like recursion/tail calls.
I saw zero reasons given for the failure to implement in that thread (which I had not seen before), other than a brief mention of stack traces (which is quite solvable with a shadow stack). All I saw were several people (including someone involved with the spec) who were bitterly disappointed about the failure to implement. And I forgot that tail call elimination was introduced back in ES5, and yet only JavaScriptCore has implemented it.
Which again leads me to believe that most implementers believe it's just not worth the trouble to them to implement a key feature for functional programming, regardless of how much the users want it (the feedback in this thread is similar to what i've seen elsewhere).
I might be way out of my depth here though; I couldn't quite grok the discussion in your link. Is there's a way perhaps you could 'ELI5' why it's pragmatic to ignore this issue?
And voila the attitude I was referring to, it comes out. Recursion is pretty damn essential to functional programming, and like it or not that's the way JS is headed.
Well, like it or not, recursion did not make it to ES6/ES7.
I don't think there's a masterplan or some anti-functional conspiracy, but I do think there's pushback. They implemented the feature behind a flag but from what I've read (can't find the reference now), they are not planning to ever release it.