Problem was that Allegri went into the game accepting that the game was not too important, he set the team up to take something like a 2-0 loss rather than being open and losing 4-0, yet the team still lost 4-0. You can only accept that kind of approach if it works but it failed badly. Obviously the clown midfield and very light options at both ends of the pitch mean we were always going to struggle, but there are ways you can accept losing a match.
Unfortunately I think we're just so inconsistent and lacking general quality. The quality we have is out of form or injured. And then we faced a quality team in good form, much better condition than ours. It happens.
As for Chelsea, this is a team who have ended up boosted by their transfer ban, but it still comes down to having an owner willing to spend. Their academy has been first class for some time but players rarely got a chance, so what they have now are several hungry, young players who have first team football behind them, complimenting an already good squad of internationals, and since the transfer ban was lifted they have spent another £300m on players. We just can't compete with that at all, but it's clear that the money we do spend has to be spent a lot better. This squad is full of failed transfers, the last two years have been dismal.