It's not like they didn't do it. They weren't allowed to do it. Brazil foiled their gameplan completely; like Bayern did with Barcelona. Spain got a great squad but they need to stop making same mistakes as Barcelona.
Barca's downfall has been lack of Plan B in their Possession Tactic and the dependence of Messi. Two drawbacks that Bayern exploited mercilessly. One of this flaw is trying to be remedied with Neymar.
Spain's forte is that they were never dependant on any star player but unfortunately, they also seem to a same dooming game tactic without any Plan B. Tiki-taka and Possession game remain deadly efficient. But at times, some coaches put up an anti-tiki-taka tactic and that's what Brazil did. As much as Barca can differently play otherwise and revert to a new tactic, I personally believe that Spain can.
They got a larger panel of players apart from the technical ones. The likes of Navas, Isco, Martinez Cazorla, Michu ect... can bring a different facet but it's up to Del Bosque to change tactics and rotate efficiently. If more teams fare the same tactic as Brazil and if Spain remain stubborn without changing, WC might not be very pretty for La Roja.
I'm inclined to agree with most, but also disagree. This is a quote from an author who wrote an article who is neither Barcelona/Spain supporter.
"It is not that opposition sides have worked them out, it's that they are no longer applying their approach with the same intensity. Five years of continued success at all levels have inevitably led to a certain staleness, removing that extra edge and resulting in the ponderousness shown when many of them played for Spain."
Barcelona have recently lack off a lot. They've made poor decision once again I heard they signed Roma Marquinhos for 32 million! a 19 year old defender. They've failed to fix certain holes in the team and most importantly have forgotten about Pep rules, you attack and defend
together. They used to pressure opposing team like no tomorrow, but that is also gone. I know old age has come with many of them, most importantly Puyol/Xavi, and as they say empire rise, but they also fall. I don't mean to take anything away from Munich thrashing and Brazil hammering as both were executed perfectly.
At this point I remember Pique comment. He said something a long the lines Barcelona aren't the best anymore, but their goal next season is to become one again, which would be the right attitude.