In reply to Pete.

Respectfully, a properly coded theme doesn't fix HTML or other specification and standards validity problems inside content. The WordPress theme space, (along with every other web space), has demonstrated, en mass, that it has no regard for standards-compliant markup. So even if it were true that themes could handle any markup issues, they don't, for the most part. As long as people are building websites, they should have learned or should be learning HTML, because good HTML underpins everything else: JS, PHP, everything but CSS. In the absence of that, any wysiwyg tools developers create need to handle that for them. Most don't. Since we're going the page builder route, then the best way forward is to ensure that users don't have the opportunity to screw up something as foundational as markup without putting some work into that. Standards don't win in the end. If they did, we wouldn't have the mess that is current javascript practice, for example. WCAG, (or at least the "understanding" and "informative" docs), would probably be a lot shorter, because it could just assume that everybody writes good HTML and CSS, or that the crappy stuff hasn't choked the internet. The first technique mentioned in every single accessibility talk wouldn't have to be "Learn HTML". So if users shouldn't have to do this, then developers should ensure that they do their jobs, and make sure that users can build websites that don't further the brokenness that is the web. I'd love to banish page builders for the sake of purity. That's never going to happen. Almost from the beginning of wide-spread adoption of the web, they've existed. WordPress can't at this point just say we're going to avoid them, and we're not going to have one in core. The community has already demonstrated that they serve a need. On top of that, WordPress either has to compete with what's out there, (basically page builders but on a larger scale), or become irrelevant. Once irrelevant happens, all the purity in the world isn't going to matter.