This is of course an artificial argument, but an argument that serves many purposes. It endows defeats with some sort of dignity, gives a legendary flavor to victories, and, most importantly, it enriches media and nurtures the business. The extreme positions adopted by both sides appear as a reasonable price to pay; they are just an anecdote of the battle.
The side effect of the good vs. evil approach to football is pretty obvious: what happens on the pitch somehow becomes irrelevant to all. What it counts is what occurs before and after the match. Truly amazing. As an example, consider Mourinho's admitted "plan" for the first UCL game. It appears that he intended to "frustrate" Barcelona during the first 70 minutes by populating the midfield with aggressive Pepe, who would cut every attack at any costs. Then, by the end of the game, with a tired and confused Barcelona, he would include an offensive player to try to win 1-0, thus getting some advantage for the second game. A ridiculous strategy, especially if you consider that it was the most convenient one for Barcelona. Then, after the Pepe vs Alves situation and Messi's first goal, the master plan failed. What did Mourinho do? Well, nothing. For instance, he could have well changed the team, to avoid any more away goals. Of course, conspiracy theories are more attractive to argue than coward tactics. Mourinho knows it, he went that way, and most seem to ignore his stupid original plan.
The victories of Barcelona are also useful to hide the fact that his players are regular football players, not the well behaved boys they wanted us to believe they are. Here I think of the acting lessons by Pedro, Busquets, Mascherano, Alves. As economy, football is cyclic process, and Barcelona fans seem to be using this positive period to install the idea that their way of doing things is the morally correct one. They want us to believe that they excel now as a consequence of some core values only them can embrace. It is a rather pretentious way of presenting what it appears to be the conjunction of a number of positive circumstances: several extremely good players at the same time, repeated failures in the past that justify hiring a young coach, a political context that seems in accordance with the rest. Would Guardiola be as successful (and pretentious) as he is now, with different players, in a different team? Most likely not. Would Messi be able to have a long career? I seriously doubt so. Would brand new Xavis and Iniestas appear magically when the original ones are not available? Hardly, even if they claim to be the factory of the "good" football. Granted: for the moment, they seem to have all the ingredients to have a historic football team. But please: do not push your luck.