I have had my rear brake bled 5 times now.
Replaced the fluid with the recommended replacement "higher temp" fluid.
They also replaced the rear line.
They just replaced the rear master cylinder.
So far (previously after the bleeds or the line replacement, the rear brake would fully fail within 100 miles), so good. Nice solid pedal feel. No fade.
I rarely use my rear brake on pavement but favor it in loose gravel or loose dirt.
Or to hold myself at a light.
So it isn't like I am over using the rear brakes.
Apparently, Ducati thought so much of the braking system that the rear MC, line and the entire ABS pump have been replaced on the 2013 bikes.