If Canon became a pure marketing company, selling a camera made of components from other supplier's spare parts bins, it would quickly dissolve into irrelevance. I'm not keen for that to happen and encourage Canon to keep making their own sensors.
Despite numerous claims that Sony sensors are better, where is the real world proof? They might have a slightly different "look", but better? I've never taken a photo and thought it would be better if I'd used a Nikon or Sony.
Anyway, arguments about sensors pale in consideration to the real issues - black and white vs colour, negatives vs transparencies, Velvia vs Provia vs Astia, kodak vs Ilford vs Rollei vs Fuji vs Fompan vs Agfa vs .... If only there was one film!