A sequence of one win in their last six matches has left them five points adrift of the play-off places, heaping more pressure on manager Darren Ferguson.
Afterwards, MacAnthony posted on Twitter:
"Like all Posh fans & our Manager, there are many things i'm well & truly p...d off & have the hump with after today, care to know them all?.
"1. P..d off that its always the manager who is held responsible when a team of players fold like a stack of cards when the going gets tough!
"2. P...d off our team can play with that kind of tempo/intensity for first 25 mins, then follow that up with the 65 mins we all witnessed!
"3. P..d off that a player of Joe Newells ability can miss an open goal from 5 yards out early on. He should be scoring 10/15 a season.
"4. P....d off that a striker I paid half a million for minutes before Colchester score scuffs great chance 8 yards out with nobody near him
"5. P...d off that Bossie allows their top scorer to get in front of him to tap in their first goal, shouldnt happen!
"6. P....d off our CB runs 50 yards to edge of oppositions box, doesnt pass or shoot but loses ball & they go other end and score.
"7.P...d off both our full backs who plenty of the ball couldnt deliver any crosses of any merit or quality or with urgency.
"8. P..d off we had a ref who cost us Crewe game cause of incorrect decision was given us again, then sent manager off & many yellows today!
"9. P...d off that as going has got tough many thousands of fans have bit like our players, have folded and taken their ball and gone home!
"10. P...d off with everything, but tomorrow ill still pay the bills & next Saturday will pay thousands to watch my team play & hopefully win.
"11. P...d off that our GK had 3 shots to save all game but we conceded 2 goals!"