I am not sure it is not a coincidence that the same idea keeps resurfacing. I remember reading pretty early on that HTML/XML/XHTML would eventually lead to a world where "chemists would have their own tags to represent chemical formulas" and similarly each discipline would develop their own tag language. Browsers would just know how to render them!
People have tried to materialize this idea in multiple ways over time - HTC, microformats, web components etc. It should not be surprising that the solutions are similar. This isn't to say the first implementation was the best, and the others have just forgotten history. I am sure there are some pretty senior web developers around who remember their history, and were even part of it. If anything we should be optimistic that the new implementations have learned from the mistakes of the past.