I believe the idea is not that they hide their motives, but that they hide from their motives. May or may not be true, but still...
Maybe it's willful ignorance. Ignorance of the misuse and harm of mass surveillance.
Do you see how impossible any dialog becomes in that model?
It's true that people sometimes don't argue in good faith, and it's fair to question hidden motives. But I think if you have better facts, you should keep arguing the facts.