Personally I think the ability to anonymously downvote a comment is socially problematic, and it creates a climate in which long-term users (who can downvote) can appear to be more intolerant of dissenting voices than they probably are.

If I could edit it now, I would rephrase it to something more along the lines of "This blog post shows some pretty nice code you can write in ES6, but overall the new features in ES6 are deeply flawed etc. etc."

Here's how to deal constructively with the situation you deplore: post stories about things that are better. Then you'll help others learn and improve, even if only a minority do so.