Lewis Page strikes again...
"(for instance armour protection, likely to be demanded) even though the flyboys' risk is fairly small"
Compared to what? Highest target on the Taliban's hit-list are the Apaches, closely followed by the Chinooks, then any other helicopter they can bring down. They don't worry so much about airstrikes from fixed-wing aircraft since they still figure to be able to get out from underneath a bomb, but the helicopters can hover and therefore catch them as they pop back out their holes; even the venerable (ie old and slow) A-10 isn't much use against an enemy doing gopher impressions.
Unless these expensive big boys' toys can be set to run over a random route every time, it won't take the bad guys long to figure out 'safe' ambush points. While the soft pink squidgy thing in a conventional heli would maneuver the heck out of Dodge and find another route PDQ, poor old Gort will just continue on into the curtain of lead and the bad guys will suddenly have a nice gift handed to them.
Hmm, maybe the USMC intend to stuff RoboHeli with a load of MREs - that'd soon teach the buggers to stop shooting 'em down!