Originally Posted by kovidgoyal
Umm no, the major problem with epubcheck is that all it checks for is the conformance of epub with various DTDs.
It's basically an extended XML validator. I don't understand your antagonism. I've certainly found it helpful in locating errors I've made while editing ePubs.
It doesn't guarantee that an ePub will render on current or future devices, but it does filter out elementary errors and superfluous fluff.