O'neill deserves it, despite losing to Utd which you'd frankly expect, the performance was terrible, Utd were terrible and yet still won and Sunderland had a single and truly pathetic shot on target. You've got to stay up, Utd play a weakened team and you drop Larsson? There is a reason the team was built around Larsson in the last few years, because he's by a mile their best player. O'neill has focused on Segnesson since he arrived and unfortunately he's a showy player with no end product, he's Gervinho basically, looks like he gets on the ball a lot, runs a lot, does exactly nothing useful in most games, gets a few goals off the basis of taking so many shots and the team focusing on him but is actually crap.
Bendtner/Larsson were excellent last year, Bendtner's movement, hold up play, choosing the right lay off more often than not and Larsson's ability to move the ball up the field, world class delivery(most consistent in the league IMHO). So O'neill decided Segnesson was worth keeping, got Fletcher who can finish but can't do what Bendtner did and what worked for the team, and basically killed off Larsson by shoving him in central midfield, still good but the team lost any drive on the wing.
He got fired because the utterly toothless awful performance today was down to misusing the team he has, buying badly, and generally being rubbish, not because Utd were unbeatable.
Fletcher's scored a few but other strikers have done as well/better for far less cash. They needed a better CB's, strikers, fullback and a non thug in central midfield, instead he did what he does, spent incredibly badly, 14mil on one player that isn't good enough, instead of 14mil on the 3-4 players they needed.