I agree with 2wheelsforme that the tire looks worn in some spots but not others AND with only 6700 miles on the tire??? I'm not familiar with the Metzler 777 but I've run 880 and 888's on Honda VTX cruisers and the wear was even. (EDIT: The wear was even...all the way around the tire on the left side more than the right side.)
First, all of my information comes from this GREAT write-up on tire wear of motorcycle. I also recommend Tires 101 from Bareasschoppers which links to the other site I provided. I think BIGLRY is even referenced on the site a few times.
In a nut shell...Normally, ALL front motorcycle tires wear more on the left or right side depending on what side of the road you drive on and it's due to leaning the bike in turns at intersections.
Road crowning CANNOT be the issue. Think about how much of an angle the bike and tire has to be at for the worn part to come in contact with the asphalt! The wear at that angle MUST be caused by a left turn, and here in the USA, it's largely due to the larger radius left turns we perform at intersections. Over time the larger radius and thus longer distance adds up by. We drive miles more in a left angle lean then right angle lean. Also the lean angle creates centrifugal force at an ANGEL to the tire. The ANGLED force removes more rubber from the tire than when it's straight up and down on the open road.