Not to say that this isn't a noble aspiration, but it is a glaringly naive point of view to say that organizations like the NSA and CIA don't need to exist.
What are they needed for? Who do they benefit, how, and at what cost? Who/what decides when the cost/benefit is acceptable? Nationalism(our rights are more important than theirs)?
I think the GP's real argument was the "at what scale, for what purpose" bit. I don't think many people want to see intelligence agencies entirely disbanded. But questioning what they do and how much they do it is legitimate.