This. Thinking that the complexity of a spec is the primary obstacle to adoption seems logical at first. But it can't be true if you consider that the specs of all kinds of "foundational technologies" we use daily - HTML/CSS/JS/the DOM, IMAP, USB, IP, etc - are not just complicated but often downright messy, full of overengeneered, inconsistent or contradictory features.
I'd argue that the "beauty" or "ugliness" of a spec can make the life of the particular programmer who has to implement it slightly easier or harder - but it has very little effect on whether it is implemented or not. That's a product decision which follows completely different considerations.