The Result of Government Accepting Payoffs (Donations) From Pilot Associations
British pilots, and their unions, have been vociferous opponents to anyone but anyone sharing 'their' airspace.
Most all of the pilot complaints have been anecdotal reports of 'drones' flying at heights when pilots simply do not have the facilities, or time, to properly identify something they are passing at hundreds of miles per hour.
Furthermore, the country with a far higher aircraft-to-drone ratio than the UK has far fewer sightings as their pilots don't lie. Sure, there was recently a drone / helicopter collision reported recently where the drone 'dented' one of the elements of the rotors but the helicopter carried on and landed safely.
My employer develops drones for military purposes - dropping nasty things on opponents - and we have flown drones into windmills used to generate power, propellers attached to engines fixed to runway concrete and even in a wind tunnel. On no occasion have the objects our drones were in collision with caused disabling damage.
The airflow over the skin of an aircraft is smoothly handled to minimise perturbations in the air and since drones share the same air, they are carried over, or under, the aircraft. I have seen no reports of any tests actually firing a drone in to a jet engine.
The British government is relying on a 'bent' experiment, that had pilot union participation. that cannot in any way shape or form be described as scientific.
Why do the commercial aircraft operators have so many interactions with Unidentified Flying Objects, and the military, who zoom across the otherwise quiet Shires of the Home Counties disturbing cows and dozing senior citizens, do not have reports?