All this controversy and heat around the Clasico is happening because of Mourinho and his obsession with taking, or trying to at least, all of the credit away from the opposing team. "It was luck", "It was the referee", "It was the rain", "It was..." etc. The only time he couldn't really complain about anything was in the first Clasico (The 5-0) but even then he insisted that the gap between the two teams is not as big as it seems. After getting mauled but a majestic performance he had the guts to say something like that. On top of that, his way of cannibalizing a game and making it revolve around referee decisions while he persists his players play a more than simply aggressive role is really getting on the nerves of our players and it shows.
Some would argue that this is entertainment, and i would agree if it didn't reach the heights it did this and last season. There's a nastiness behind Mourinhos game that is really repulsive and makes all of his accomplishments seem like nothing to me.