Swing and a miss Yahtzee, swing and miss...
Yes, BC2's single player is shamelessly "borrowing" the setting, to put it gently, from MW (the original, not the shitty sloppy seconds). No, he gameplay is totally different. Yes, the single player totally needs work (although I'd argue you were just playing it wrong, considering I didn't have much of an issue in the mortar stage... Run).
With all those faults, it still offers the best experience I've ever had in a game. A great part of it is the MP, and we all know you don't review that, but considering the MP was largely the focus (and the SP was more of a secondary "bonus" experiment) you really should have given it a try... Then again you reviewed Borderlands as a single player game, which equally confused me (despite the fact that I don't particularly like it).