Bill. You are better than this.
I could make shit up (like some do on here) and say he had no other option because everyone else avail was carrying a knock, or everyone else was piss poor in training all week, or nacho was injured/feeling unwell. (being factual, he hasn't scored every time he has been on the pitch). I don't know why he picked Bony over Nacho, but he will have his reason (maybe didn't want to risk injury as we need him as back up for Tuesday - I don't know, and I would suspect no one on this forum knows).
The simple matter is that we do not know what constraints he has to operate under and with what resources he has available. That team he selected against the bar codes was more than capable of beating Newcastle (irrespective of what positions they played in). The fact they down tools for a day, well no manager in the world can mitigate for that. Would you agree?
To suggest he is deliberately throwing the league is nonsense and I think deep down you could possibly see that. We are probably one of the worlds best clubs and to have a manager being a loose cannon with the reputation of the club, is not something I could see the board sweeping under the carpet - do you?
As I said, I understand your frustration at where we are in the league, the way we are playing etc, and I too am royally disappointed, but IMO, no way is Pellegrini deliberately doing this to harm us.