Originally Posted by charleski
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.
My thoughts exactly. Epubcheck may be limited, but it has its uses. I'm guessing Kovid's main objection is that people use it and think "if it passes epubcheck, all will be well" when it's likely that it won't be.
But that's the problem of the users, not the tool. Epubcheck makes no claims that it is the be-all, end-all epub checker.