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.
Replace those giant turboprops with ducted fan technology, and all those problems you mentioned are solved. PLUS, the aircraft gains in much quicker maneuverability.