I'd say it was a minority of writers that were handcrafting XHTML. And it was the case that everyone or their handcrafting or using tools could validate their compliance using a browser which made it very easy to adjust your tools or your handcrafted code. We are now in a situation where there is no schema for HTML.

I, for one, am very much in favor of forking the web with a document format with a schema. It really seems like a small and simple change to me.