I think the most likely reason H2O probably stopped caring, is that he made a savage amount of money. Everyone talks about percentage of mining income as fees, but that is irrelevant compared to some of h2o's potential takes while running MC. Consider that MC was mining the majority of Dogecoin for a week before it hit cryptsy (as in, MC represented a majority of the network and was taking most of the coins). H2O wasn't selling this on any exchange, so what do you think he was doing with it? H2O was almost certainly spending BTC from his pocket in order to buy doge. He made this fairly clear when he said that in this thread that the exchange rate was being determined manually.
Would you care about running this pool if you had bought 500BTC+ worth of Dogecoin back in December, and sold near the peak?