I bought AC:B on console for the same reason that you got AC2, and I probably wouldn't have bought Spore if I'd known about the DRM ahead of time.
The Online Pass system doesn't bother me at all, for the reasons you listed: if I'm gonna play multiplayer then I'm probably going to buy new. On top of that, I don't play multiplayer very much, so I really don't care if they restrict my progression (though it might bother me if they locked me out entirely).