I don't disagree with your assessment of United. But you have to look at the rest of the league as well and while United have regressed badly, so has the rest of the league. Who could challenge them? On paper: City, Chelsea, Arsenal. In reality:
City: Coached by an imbecile. Has Agüero, Dzeko, Tevez and Balotelli in the squad and publicly moans about the owners not spending money on RvP. Tells the whole world that Tevez will never start again for City just to make him his #1 striker the next season, benching the likes of Dzeko (who's their most on-form striker at the moment). Publicly blames his players for making mistakes. And then he fucks around with 3 man backline formations, acting as if he was Pep Guardiola. Except that he's failing hard at it. Probably took a look at Serie A and thought: "Hey, herp derp, I'm an Italian coach too, if Napoli, Udinese, Juventus and Fiorentina can play 3 at the back, I can as well!" City didn't win the league last season. United lost it. 8 points with 5 games to go. Yep, United definitely lost it (and only on goal difference as well), despite being so shit that Basel kicked them out of Europe.
Chelsea: Torres =
. Mikel =
. Lampard =
. Terry =
. David Luiz =
. Ramires = good. Mata = good. And Oscar and Hazard are 20 year old talents. 20 year old talents don't win you titles. They'll finish behind Arsenal.
Arsenal: Well balanced all over the pitch this season. Cazorla makes them forget about Cesc. Solid at the back. Podolski will always bang them in. Still you feel that a world class striker is needed. And at the end they are Arsenal. They always find a way to bottle it.
So, yeah. Another United year due to the lack of serious competition. What is it again? 12 Premier League titles but only 2 CLs in 25 years?