That's pretty much the standard wear pattern exhibited on many bikes - not only BMW. In the tire industry they call it heel-toe wear.
My local tire shop guru says it happens even on car and truck tires that have the little "islands" like yours now has. They rock on braking and wear off the ends of the islands. The only thing you can do is look for a tire that doesn't have that "island pad" appearance. Maybe your Z6, or better yet a non-metal belted Avon AV-45 would exhibit the wear less (not as rigid and may flex better than a steel belt that would rub off the rubber easier). No doubt there are others.
I'm not really partial to tires that have the tread criss-crossing in the middle either. Too much buzziness in the bars for me.