You would spend £35 on a night out , and as I said most people are buying this for the single player.
Try reading.
Actually probably 99% of people buy cod for the multiplayer. Probably more, and play the campaign through a couple times at most. Hence why so many people who are no longer interested in the multiplayer have said they will just torrent the SP (not me) because it's not worth the cash.
But why would you spend 35 pounds on a companies product who has basically given you the two fingers? Let alone when you can get that product for free (and play your precious single player)