As I understand the points being made, the V-22 ended its Iraq tour with a final MC rate of 62% (the first several months were reported at 68% as I recall). I also remember that the USMC kept the same airframes in Iraq and rotated squadrons to keep the pressure up to test the airframes and logistics.
OK, so we see 62% Mission capable and now some ppruners are ready to toss in the towel.
Can I suggest you read the MC rates for all the military equipment, including ground vehicles? Here is the source:
http://www.gao.gov/new.items/d06141.pdf
Here are a few plots from that document:
Considering that the 62% was the end of the Osprey's first active duty deployment, and it tends to match several years worth of experience for several major, mature combat aircraft, I think things aren't so bleak.
Of course, I don't have an ax to grind, and I do have data. That makes me ill equipped for this thread.