I don't really care what ebooks look like on devices/apps I'm not reading them with. I fix them up if they just need a tweak here or there (only if it really bothers me when reading), but I don't typically run into "horrible" formatting that I can't "just read" very often. When I do, I don't try to fix it, I chuck it and look elsewhere (or do without).
We already have "standards" for formats that are ignored by sellers/publishers, so why would display standards across different proprietary devices/apps have any better chance of succeeding? And if such a standard
were to succeed, why would I want an ebook's appearance to be limited to the capabilities of the lowest common-denominator devices/apps?
By the way ... Moon+ allows me to view ebooks every which way under the sun except, it seems, for the one way I
want to view it. I call it The Great Homogenizer.
Wonderful for those who want every single book they read to look exactly the same (layout-wise), but I prefer a little variety.