While I post under my real name for all the obvious reasons, namely to minimize how many stupid or mean things I say, I very often wish I did not. There's something lost when speaking for the world to hear: how many things will I say that might make me look less than awesome? (har har, I'm sure you could dig up a few). So I tend to go for the conservative point instead of the crazy idea that might be totally off the mark. It's not about "speaking truth to power" so much as speaking the truth about yourself.
It's hard to put it better than Adam Kirsch, albeit in a different context:
The essayist is concerned, as a fiction writer is not, with what the reader will think of him or her. That is why the new comic essayists are never truly confessional, and never intentionally reveal anything that might jeopardize the reader’s esteem.