I dunno. High-bypass turbofans aren't too keen on ingesting debris, and if you're pushing all that air you're going to have to deal with sucking FUD from your jetwash.
Meh, every jet has the same problem. Doesn't matter whether you're a Mig or a 747, sucking a bird down the intake is going to hurt.
Also, debris will smash your windscreen or undercarriage just as easily as a turbo-fan (
Cough,
Space shuttle disaster cough)
So, let the VTOL's go through. I don't recall any reports of Harriers getting screwed with an intake fan, and it would affect Helicopters more than this thing, but Helicopters are still in common use in busy city airspaces....