As much as this churns my innards, I'm going to respond to this (and probably regret doing so).
The first 3/4 of your post are worthless, so let's get to the 1/4 that isn't: the last sentence.
I'm dying to know how "speaking truth to power" is central to anything. Explain, exactly, how that works? If I tell a banker that she's a stealing cockroach, how does that change her behavior? Has it yet? If I tell the CEO of Lockheed that his drones are killing innocent people for bloody money, will he stop? Has he ever?
Aside from being a tedious cliche at this point, it's also utterly nonsensical. You can speak truth to power all day and power largely just cackles like Mr. Burns from the Simpsons. Where speaking truth matters is not to power, but to each other. To ourselves. That's the truth speaking that can effect the beginnings of change. Power doesn't give a rat's patoot what you or I think.
Btw, for the humor challenged, my post was largely referring to the specific phrase as a tired cliche, not as a challenge to speaking truth in principle. Bye now.