Outside of a few bits here and there, I have never watched the show. From what I've heard though, especially the last few weeks, the show has become in the eyes of some fans, anywhere from "just bad" to "total abomination", and this has been happening to some degree since the show ran out off book material to draw upon. As for a reaction, that this kind of agreement would be struck makes sense. Both from a logistical and $$$ standpoint.
Well they didnt run out of book material though, they deliberately branched off after book 3. If I recall, at one point GRRM stated that he thought it would take 3 seasons to cover books 4+5 but they managed to streamline them both into a single season and that was when things really went downhill.
When the herd loses its way, the shepard must kill the bull that leads them astray.