IMHO as much of a problem are the owners who cann't see anything wrong with forking out to fix things that should not have gone wong in a relatively short period of time. They will vociferously defend any faults on the bikes 'because they are the best in the world' and things like exploding gearboxes on 1100's, FD failures on 1150's and various 1200 relatedfaults are acceptable.
BMW now rely heavily on a reputation of reliability they no longer deserve and the loyal blinkered owners who pay whatever their stealer demands for sub-standard machines / parts / servicing.
Just got back from my Alps tour and the bike has a knackered clutch, warped discs and leaking fork seals - at 14k.
Surprisingly (well to me anyway) the FD is still running OK and I did not need to deploy my spare FPC - but I don't want to risk another tour on the bike next year when it will have a rather high mileage of 20k on it as it is falling apart like a cheap watch at 15k.
The rebuild option, although financially viable does not get around sods law, which is that it will fail on the first day of your once in a lifetime trip - who is gonna rebuild before every holiday
A cut price deal for p/x old for new by BMW would be excellent, if they offered a £500 upgrade from older to newer types I think most owners would be happy, can't see them doing it though.
I personally am not convinced the rest of the bike is durable enough anyway, and with the prevailing attitude of paying any price to have a BMW badge I can't see BMW doing anything to improve the situation or even make the next GS any better - they know tens of thousands of owners will trade up regardless of how crap the new model is.
I met a German chap on tour who came over as I was waiting fot eh Mrs to get some stuff from a supermarket, he thought I had broken down, I explained the bike was runnign, but with a few ailments, he told me the cluthces are weak and the fork seals always leak.
He had just bought a new model and seemed almost impressed at the fact the last one buggered an FD, Gearbox and had leaking fork seals the dealer refused to fix as they said "they all do that sir" and they "don't do anything so there is no need to worry"
After that why on earth did he buy GS number four

It is these people that keep BMW going in the direction they are and continually lowering quality - they will continue to do so until the sales drop.