It's no coincidence that at the same time BMW introduced "free" maintenance, they began drastically extending the maintenance intervals recommended!
I keep my cars a long time -- intermediate oil changes are fairly cheap engine insurance. Plus you never know when the mechanic will spot something potentially expensive or hazardous during the service. The shop I use always does a once-over inspection no matter what the car is in for, even if just for an oil and filter change.
Over the years, they've found torn boots, leaking struts, worn shock mounts, tires worn on the inside where it's hard to spot, etc.