I agree the players have to start taking more of the blame.
In some ways we have the same complaints I remember that were being placed on Mancini:
No plan B
Too slow in the build up
Don't know what to do in the final 3rd/quickly run out of ideas and give the ball away leading to loss of possession or worse an immediate counter with lots of space left open.
In other ways they are the opposite:
Mancini was volatile they said, this was seen as a cause of many instances of disharmony in the team which clearly affected our whole teams form negatively, it was never more obvious than when Dzeko threw a bit of a wobbler having been subbed off and then Tevez refused to come on the pitch. It's not as if this was a one off moment we caught a glimpse of either, there were many moments like this in his reign.
Pellegrini is too relaxed they say, players are getting along great but when they aren't performing he doesn't seem to hook players off soon enough(sometimes due to lack of options this season) and appears to offer not offer anything from the touchline(although he would say they already know what they should be doing they are just not doing it) in the form of instructions or encouragement.
When I think of it both managers have their weaknesses but we could have done far worse than either of them, they are both very good in the grand scheme of things especially with who was available at the time they were appointed. In some ways they have under-performed against lesser teams and in some ways fans are expecting maybe too much of the squad we have for example with our Champions league performances.
Personally I don't think overall Hart, Zaba, Kompany, Silva, Aguero are right now(under Pellers) or have ever been players you could level too much blame at, the talent is there, the effort is there, the desire is there in all of them even when they aren't "at it" you can see it... so who else is left of the Mancini era that was making noises about his style of man management being a problem? Not many at all; Yaya, Nasri, Kolarov all good enough players on their day (especially Yaya) but sometimes you have to ask is it really down to the manager when players show the same patterns of inconsistency and lack of drive under two totally different managers? I think we may have seen the best out of all of them and a change would be good for them too, I wouldn't mind keeping Nasri for one last chance at it but wouldn't argue if he went. Otamendi and Mangala need to show they can form a solid back line together or one of them has to go (remember Boateng before being too hasty).
Our squad is strong but is it up there with Barca or Bayern? No especially Barca look at Messi-Neymar-Suarez, it's very rare to have 3 players like them all in the same front line, they can all play anywhere they want upfront and would still be considered among the elite in whatever position you put them in. Their fullbacks and midfielders are also top notch, center backs you can never be sure how well they would do in the BPL but they are certainly high quality.
So all in all we've had situations where we've had to pay over the odds for some players compared to the more "established" clubs in Europe and we brought who we could in while trying to dance around FFP which when you put the two together isn't easy. There were players we might have brought in who we deemed as too expensive such as Cavani(I wonder how PSG isn't seen as the main target of FFP rather than us when you look at alot their acquisitions) but that's just how it has been for City. I feel that if we do go further than expected in the Champions league(thanks to a kind draw) we'd be much better placed to pick and choose and less likely to have to pay over the odds, so whoever was in charge next season(i.e even if Pep wasn't coming) would have an easier time of getting us up there with the best of them.