Por que os ebooks estão cheios de erros de digitação?

It seems that pushing updates to ebooks isn’t a simple or quick process. Believe me, I’m dying to report specific typos, and I think this is one scenario where crowdsourcing could be helpful, but so far, it’s just not happening.
This seems completely insane to me — the technology should allow us to move fairly quickly on pushing updates of minor typos for new purchasers of a book. This should be one of the great advances of ebooks: that if the printer makes a mistake, everyone doesn’t have to live with it until they sell through a million copies or whatever. Instead, I’m needlessly looking at typos that surely thousands of other people have seen in the past few years
We can assume that this won’t be a problem with most new books, because printed and digital versions will be created simultaneously from the same master text… unless publishers actually get lazy. But most books aren’t brand new, and if the convenience of an e-reader must bring with it an acceptance of shoddily produced and edited versions of books, then count me out.

Why is an ebook ever riddled with typos?