Earlier quoted context omitted.
It would be more correct to say that they never deal in truth with the public. Of course they are a source of well researched and painstakingly obtained truths for government decision makers, but never for the public.
Not true. Take cyber threats for instance. Govt makes public disclosures all the time
The good part about releasing information about exploits and such is that they can be easily verified to exist, so there is no need to trust the spy agency. Any claims they make about the source of those exploits is not easily verifiable, and since you can't trust them, should be ignored.