Yes, this squad has limitations but his weak mentality and lack of a solid plan get exposed at the highest level. We don't have the legs or work ethic? Maybe it's time to start integrating the youngsters and benching or selling the seniors? Instead he plays guys like Suarez and Rakitic game in game out. I guarantee a guy like Mourinho would have played the same dogshit style as Shitverde but we would have made it through both of those matches instead of collapsing in a heap.
Shitverde has no balls either on or off the pitch.
I understand what you're saying and in theory the solution is very simple, isn't it? Bench the old, physically incapacitated seniors and inject youth and fresh blood into the squad!
In practice this situation presents the coach with many more problems. EV had two options:
1. Compromise his tactical authority to play the experienced heavyweights of the squad, whom despite physical decline still possess world class technical qualities. This keeps the big names on his side and is the safest of the two options by far.
OR
2. Bench the senior players to impose his style on the team and opt for unproven, less technical players that have the legs, but are probably not good enough to command starting spots at a club of this stature. This strategy has major risks with the new players possibly falling short of fulfilling expectations and the seniors tuning against him.
At first Valverde tried to impose his tactical structure on to the existing core of players and after realizing they didn't have what it took play his brand of football settled with option 1 of keeping the big names settled and giving them the license to play the football they are most comfortable with.
Valverde is not the coach to kickstart a revolution. Sacking him only to bring in a small fry like Koeman or Martinez would have been a mistake. They're much more limited managers that despite also giving in to every whim of the senior players would not be able to grind out results in league as effectively as Valverde has.
Ironically EV's now infamous "It is what it is" quote is the perfect way to describe the club's current situation. A fresh team is on it's way, just wait a few more years. Now is not the time.