If we don't want that to happen then the smart thing to do would be act as if that is what they are proposing.
If they propose something even worse it isn't like it will have been wasted effort.
Did you mean to say it's not elected government officials? Just curious, because I definitely consider a country's intelligence apparatus to be completely and wholly part of its "government", and would be surprised to find someone who didn't.
The security services have a large amount of operational discretion and privileged access to ministers. They have the ability to present secret "evidence" which cannot be publicly challenged.
Let's not forget that the CIA effectively ran the governments of several Latin American countries, and in the UK Northern Ireland was effectively governed by the police Special Branch.
The book does veer somewhat into unfounded conspiracy territory, but I think it's an interesting read so far and the author doesn't come across as crazy so much as skeptical.
And there is the essence of why we want transparency, oversight, restricted privacy etc. I generally feel that if everything the security services did was publically available (at least on level with civilian police) there would be a lot of friction but they would get immersurably better.
I was trying to say the security services will always press for more powers and it's the job of politicians to know when to resist those requests.
My American friends were mightily amused and amazed when Belgium spent >500 days without government a couple of years ago, but of course they were interpreting the word in a much more encompassing way than it is done in Belgium. 'The goverment' is really just a couple of dozen people (with perhaps a couple of dozen assistants each).