On one hand, yes, all true, it’s definitely a bit of a mess. On the other hand, what’s the alternative and don’t all languages with limitations ultimately get extended by various parties in non-compliant ways? Can anyone point to any alternative that has done it all correctly? Show me one language where someone says “This is all good and correct” and I’ll show you a language with 100 feature requests to extend it way further than its original authors intended and would create a similar mess if acted on. This is all to say, I’m going to coin Roberts’ Rule which says “All markup languages eventually end up as piles of poo with half a Turing-complete language bolted onto the side. Resistance is futile.”