It's a proven fact that 100% of football players eat food, breathe air and need a place to sleep. As such, fluctuations in economy affect them as well. Celebrities are humans, and they are not above reproach. As representatives of their nation in other parts of the world, it's important for morale of the team that the country be in order just like it's important for morale of the country that the team be in order.
I don't know how much Spain's struggling economy has impacted their football team, but it certainly has, at least a little bit. When you consider that the players are affected by economic struggles like everyone else in Spain, it's easy to see how their performance would worsen. They may just have too much on their minds to play effectively.
Money is the root of all evil and it would appear the Spanish team as come to realize this. Rather it's personal financial problems with the players or reduced spending for the team overall it's difficult to say. I think economics and money problems affect more people than we realize or that people realize in general.
It's hard to believe that financial stress would not have an impact on the players performances. Not only the worries for the country as a whole, but personal stresses that are an effect of the economic crisis. While there may be other, more prominent, factors that led to their defeat, the smaller problems just build on this to create a great impact.
Spain was overconfident and looked down on their opponents. They thought the could go through without s problem as they won the lat WC, this allowed their opponents to pull an upset and win. This also happened to Italy 1950, brazil in 66, France in 2002 and Italy in 2010. So it is not the money which lost the WC in was the mindset