Eich was a person that could have made the entire situation disappear in an instant by making a (completely meaningless given their history) matching donation to the HRC, and issuing a short post apologizing for his actions. Sure, many would see right through such a transparent act; but it would completely deflate the opposition in an instant -- guaranteed.
He didn't do so. To this day, he's still completely unapologetic for his actions. As much as I dislike the man, the one thing I cannot fault him for is that he is a man of integrity. I don't see him lying and pretending he voluntarily resigned.