Well if it wasn't for La Decima this year I would have been crying after the Chile loss. I missed the first game thankfully because it was the same time as my undergrad graduation ceremony.
Everything that could've gone wrong with the team went wrong.
The 30 man selection should've been better including guys like Fernando Llorente, Carvajal, Inigo Martinez and Isco and excluding guys like Torres, Villa, Albiol and Juanfran. The starting XI selection was not up to par. Lots of players were recently injured/not match fit (Diego Costa, Busquets, Alba, Pique).
Iker not playing in La Liga really f**ked up with him as evidenced by his last 3 games. However, despite that, in the Copa del Rey and UCL (aside from the final) he was pretty phenomenal and had crazy statlines (ridiculously low goals condeded average and really good saves/goal and per game). But to be a goalie you really need to play every week.
Xavi had a horrid season with Barca and it clearly showed. Physically he has lost a lot. And he can't pressure and defend like he used to. Alonso looked horrid against Chile, had a pretty big part unfortunately in both of the Chile goals. The d was horrid. A goalie is only as good as his defence.
Tactically VDB got it wrong in both games. Losing 2-1 vs Holland and he switches strikers (smart choice), but he takes out a CDM in Xabi for a winger in Pedro, leaving in Xavi. 1 minute later Holland scores. Then 2 more goals. Busquets alone cannot shield a back four. Then in the Chile game he took out Xavi (rightfully so), put in a winger in Pedro but had Silva in front of Xabi. I really thought he was going to put in Koke as Koke is much better defensively and we'd lose some possession/offense but be much more solid defensively.
The great thing about all of this is that now changes must be made. The future still looks bright - Jese, Isco, Thiago, Carvajal, Oliver Torres, Deulofeu, Inigo Martinez, Morata, Bartra, Iturraspe, Illarra, etc.
I think the 2016 Euros can be defended with an interesting mix of current players (Ramos, Iniesta, Silva, Cesc, DeGea, Diego Costa, Javi Martinez, Busquets, Mata, Koke, maybe Pique, maybe Azpi, and maybe Alba) and some of the above mentioned players plus some others.
Xabi just announced his intl retirement and Xavi will probably announce it soon. Reina will probably be no longer recalled to the squad and it'll be interesting to see what happens with Casillas - very big year coming up for him. I have very big doubts he'll start in 2016 but maybe he'll be the backup or 3rd choice. Valdes will probably be in a similar situation to Iker. De Gea is obviously the future.