We'd all be better off if the W3 dispensed with all that ideological semantic purity BS and started doing more realpolitik. Think not about whether your API is semantically pure, but about what developers want to do, what hacks they'll use to achieve their goals despite your objections, and how to enable doing those things in a way that is maximally beneficial to everyone involved.
ARIA live regions are the perfect example. What developers actually want is `document.speakText`. What developers actually have is a weird API that announces text on the page as it changes. They have to bridge from one to the other, which is difficult and hacky, even when implemented well. But hey, at least that live region approach is semantically pure HTML...