Re: because GCHQ et al
Since the local plods are thoroughly outgunned when it comes to people that eat this technology literally with their morning pizza. There are quite a few talented ones capable of the work but being understaffed already... it just goes by the wayside. They're used elsewhere.
Now the intelligence agencies are deeply reliant on the same technologies as the "hackers, crackers, ..." crowd and have nice depth of talent. Still nowhere as good as some of the better enterprises but not do to lack of funds. Black budgets mean black contracts if you can't do it in-house. And we saw where that turned around and bit them in the balls with the consultancy that Mr. Snowden worked at. Heck, even before he left direct employment by the government (Air Force?), he was getting schooled on penetrations and other offensive operations.
Do remember, that "Black Ops" doesn't have to be entirely cyber. It can include bringing a gun to a byte fight, not a unwieldy club which is about where most people operate.+