When an alternate display method comes out and wants my semantic html, I will add it to my QA workflow and make sure that it looks good instead of relying on some vague standard of semanticness from one of many bloggers.
Sure it's mostly black text on white backgrounds with only minor typesetting differences between elements but as a means to present information it has worked since the mid 1400s...
The more page authors use html 'properly', the more incentive there will be to improve systems like reader view.
This comment made me realize how relative everything is. It seems it was yesterday, when you would open Mosaic and slowly discover completely different worlds, one after another, and you'd never think of complaining HTML was aesthetically unpleasant...