This would be more convincing if even DP knew how to reliably put their ebooks on ereaders without degrading them. And then offered to do it.
In my humble experience many people who volunteer at DP, and many of us who generated "HTML" books directly for PG are working quite hard to do so in a way that will work well for EPUB and MOBI (Kindle). It doesn't help that many of the implementations of the reader software on one or another ereader reader or reader software is more or less whacked. Not that HTML browsers are that much more reliable either. And a basic problem, again, is that HTML is not well suited for describing even pretty simple things that need to be coded in ebooks. It is also not clear to me as one who codes this stuff just how much effort *should* be put into coding HTML that looks pretty on one or another ereader -- this stuff is evolving pretty darned quick now, so its not clear to me how much of this effort is really worthwhile vs. how much will be obsolete six months from now. [But the advice in the wiki EPUB article seems to be good advice in any case.]