Those are the only reasons I can think of myself, Stanley.
I think 4th place was of the utmost importance this season, and let's be honest, with the poor form of Chelsea and Arsenal this season, it was well achievable - unfortunately for us, we've been even worse - results-wise anyway.
I think if the team continued to look promising, but missed out, finishing 5th, but with one Cup - maybe even 2 - in the bag, then Kenny's job would have been safe. Unfortunately, the league form is going downhill, and we're slipping further and further away, at a time of the season where we should be actually pushing and going in the opposite direction.
I think the Arsenal game was a killer blow. We played very well in that game yet couldn't get the goals to kill the game off and got sucker punched, coming away with nothing. Had we won that, we'd have been firmly in te race for 4th. Defeat virtually ended our chances of CL qualification, and perhaps that's the reason for the demoralised performance by the players against Sunderland. If the final nail wasn't in the coffin before then, it certainly was after it.
This comes down to mentality, for me. The team cannot ever step onto a pitch in a Liverpool FC shirt with that mentality. It should never have been allowed to happen, and as it did happen, you have to look at the motivation and leadership - which, for me, is lacking.