Apple went bad, so we don't get any watermelon? BTW, how come we don't have any contra-rotating helos like that way- cool Kamov Alligator K-52. It is super maneuverable, has a high top speed and carries one hell of a load of armament ... and is cheaper than the Sikorsky, which looks like a Jr. High shop project with all that protruding hardware. BTW, now that the V22 Osprey has shed its crowd-killer rep, how is it really doing? Anyone know?
The problems are three fold; higher maintenance on the rotating equipment, problematic maintenance (A cherry picker type vehicle is required to get to the top rotor.), overall height (They will not fit on any ship we have - too tall.).
Those are just the main issues. But some new stiff rotor designs are coming along that may make a lot of these issues go away.
Time will tell.