[MichaelGG]

Adding data and calling it a comment isn't really a comment.

And I find the whole "run minifiy/strip first" to be a hilarious suggestion from Douglas Crockford. It can be rephrased as "If you want comments in JSON, for a config file say, then don't use JSON."

That, and XML requiring the tag name in the closing tag, are some of the obvious, silly, mistakes. XML in particular. Without the named closing tags, just using, say, <>, would reduce the apparent bloat and annoyance by a very large factor.