Bought a set of Ferodo semi sintered front and rear brakes about a year ago, installed the rear ones but the front ones seemed fine. I just had another look at the front because there's been a very small bit of squealing recently but they appear to have about 3/4 of the tread left compared to the new ones I held side by side. There's 53,000kms on them so far and at this rate they'll go for another 50,000 kms, this seems a bit excessive to me. OK I am a big fan of engine braking but even so I'd expect a bit more wear by now.
Maybe you don't weigh very much, do a lot of highway riding on flat roads, and use the engine and lots of rear brake to assist in braking.
Even with 40,000 miles of mostly in-town riding in hilly areas and frequent 2-up riding, I am only on my second set of brake pads. For all its problems, at least the GS is easy on the consumables (tires, brakes, chains).
Brake pads that stop well and last a long time are a good thing. If you want them to wear more be harder on them....
Well they do stop well as I'm always checking my emergency braking technique, so I guess I can't complain. 40k miles that's 64k kms, and I'm only about 1/3 of the way (if that) through my first set after 56k kms. This seems as strange to me as the people who claim they only get 150 miles on a full tank.