Zero-sum game

I don't want Spanish teams to be eliminated from the Champions League. On the contrary, I would love to see Valencia and Malaga, who both lost their first last-16 matches, to go through.
But there is nothing I wold like more than to see Real Madrid and FC Barcelona eliminated. So it was with delight that during a trip to Colombia I saw both struggle in their initial last-16 matches in the CL. Real Madrid fought their way to a 1-1 result at home to Manchester City, while FC Barcelona fell to a superior and intelligent AC Milan side 2-0 in Milano.
Both Manchester United and AC Milan know that there is a long and difficult match ahead, but truth is that they will be doing the football world a favour.
I am just tired that this rivalry defines football, blinding to the many other great teams. These two teams only exist for each other. Granted, it is fun to watch them play each other (as today, where Real Madrid trampled over a poor FC Barcelona side), but their glory is not a zero-sum game where ones loss is the others triumph! In fact, the loss of either side, in particular in the Spanish league, may propel other teams forward and give renewed excitement to a pretty lame league.
The same seems to be the case in the CL where the "dreamed" final between Real Madrid and Barcelona has fortunately not taken place, and hopefully won't.