One nice thing about most lightweight markup languages is that they do not rely on English words for tag and attribute names or keyword values since they are repurposing ASCII punctuation/non-alphanumeric characters instead. All those extensions with key-value pairs and explicit names harm that principle. They are a step back. They are not based upon prior art, i.e. actual practice in plain-text media. They are not in the spirit of Markdown. They impose coder habits onto a general purpose language. They must be considered harmful. They are a bad idea.
That being said, there is a place for names that are not predefined, i.e. IDs and classes, or that are proper names, e.g. language names for automatic highlighting in code blocks. IDs can be auto-generated, however, in most if not all cases.
In other words, if you want verbose tags you have come to the wrong place and should use XML/HTML or (La)TeX instead.