but the most stupid thing they did was letting Yaya Toure go. Busquets is OK i guess but hes to slow. he cant cover alone for all the players upfront (Xavi, Iniesta, Messi, Neymar and even Alves who doesent even bother to run back like hes f*cking Robben and doesent need to defend). they know they will get countered every game and play with only one DM (who is slow as shit. yeah, he "reads" the game good but thats really irrelevant when you have 2-3 players running on a unset defense) and a fullback (Alves) who is 70% of his time on the wrong half of the field. i mean, i hate them and couldnt care less if they finish 5th or 10th but they really are stupid...
This failure of theirs is a result of more than one reason, of course. Letting Yaya go could be considered a reason, but I don't see it as an important one. After all, for many years they did great without him.
In regards to some of those reasons they couldn't do much. They can't stop Xavi and Puyol from aging, or Messi from getting injured. But some choices they made were borderline stupid. In both their CL winning seasons with the tiki taka they had a striker, and I mean a real striker who moves well and has the goal scoring instinct. First it was Eto'o and then Villa. That's exactly what they were missing in each of the other seasons post 2009. In 2010 they had a great striker, Zlatan, but he didn't have the characteristics needed for this kind of football, which Eto'o and Villa had in abundance. In 2012 the attacking trio was Pedro, Messi and Sanchez, neither of which is a pure striker. Villa was rarely getting games that year. Then Fabregas also found himself in the attacking trio and now Neymar is there, despite not having the needed characteristics of a CF. The moment their attack became Messicentric, was the moment they stopped winning in Europe.
In 2009 Eto'o and Henry scored 62 goals (Messi 38), in 2011 Villa and Pedro scored 45 (Messi 53), in 2013 Sanchez and Pedro scored 16 (Messi 60).
And then they even allowed Messi to pick the coach.
Like I said, there is little they could do regarding Xavi. A huge figure for them, and extremely important one. He's aging and you can't replace a player like him. They managed to find solid replacements for Henry, Yaya or Abidal. But they didn't even bother to find a replacement for their leading figure in defense (Puyol), they didn't react to Alves' aging and, the main one, they don't have a pure striker now. Both Sanchez and Neymar are players who'll play support strikers in most of the teams. They sacrificed the team's results for Messi's numbers and wishes.