Having worked on the BCU for 2 years I can honestly say it is a vital cog in safety, a Nimrod went down about one year after I arrived at RAF Kinloss in 1983 due to ingestion of a flock of about 400 seabirds. A New Zealand Air Force pilot on a secondment lost his life, the birds were cleared from the middle of the runway but settled at the end of the runway, the result was they lifted as the aircraft rotated and the aircraft crashed in the Rozelle woods.
Well that goes to prove that having a dedicated BCU is no more effective than having the wildlife dispersal done on an irregular basis.
In fact it could be convincingly argued by no fee no win lawyers that the BCU operator at Kinloss contributed to this accident by failing in his professional duties and dispersing the birds from one point, but failing to ensure that they had been dispersed away from the runway and approaches.
Worthy of thought for anyone involved in BCU operations, especially Safeskys and the individual BCU operators in a similar situation - you would both be equally culpable.
A bird control unit can't be everywhere at any one time and unless the operator is omnipresent and precisely because of the above, airport authorities are highly likely to go for the option of not having dedicated BCUs.