The life the engine has had is what shapes what you see under the cam cover.
Lots of cold starts, a cold climate, and an adherence to 15k oil changes seem to promote it. I've looked at engines at work that get their oil changed every 700 hours (that's about 30,000 miles!) that are completely spotless. But they get started once and run for up to 3 or 4 days at a time. They don't ever experience a cold start, run for 10 minutes at 0F, then shut off (like my e46 does).
But even at that, there really is no harm. It's disconcerting, but the actual vital parts of the engine RARELY actually wear like they did in the old days. With that in mind, we undoubtedly obsess about our oil way more than the evidence indicates we should.
When's the last time anyone has seen a bona fide wornout BMW engine that wasn't abused or neglected?