Funny you should mention that. These non-standardized descriptive names are included in every element, but they don't help much for building standard processors. It does have this modeling capability that lets people agree formally and unambiguously exactly what those labels ought to be. You seem to be saying that all we really need is something like HTML, where everybody already knows all the element types and all the semantics. I thought XML was supposed to take us beyond that paradigm.
Generality is good, but ambiguity is a vice.
Ambiguity in this case is a vice. If the former, then we're not talking about the same thing. If the latter, you're condemning something that doesn't exist yet. You can't have it both ways.