Everyone in entitled to their opinions on oil changes. Its almost a religious thing for some folks. And lets not even get started on WHAT oil brand and grade to use.
My main thinking, is I plan to keep my car a long, long time. Oil is the life blood of the engine. I think oil is cheap(er) than a new engine. Especially when you see how many problems these engines can have with Vanos or Turbos, ect... To me it is just common sense to change the oil more often than every 15K miles(or once per year) like what BMW says too.