Yeah, sorry for the bluntness, but this is an economic problem, so only having a conservative point of view is trying to think it and solve it while looking at it through a pair of glasses with only one lense. I felt I had to show you did get something back with the new model, better MP, a thing the "all private content" model had serious problems with.
Basically, if you restrict content to the DLC/Expension and dont support "free" content through the patch, you restrict MP among those who have bought the same DLCs.
I guess someone who paid for the game but not for the DLC could rightly feel ripped off if after each DLC, his possibility to enjoy MP would go more and more restricted.