Ken,
There was a time when I would have agreed with you, but I think we as a society have lost an awful lot of the restraint that used to aid in constructive social discourse. I am in a profession where my colleagues and I review each other's work, and negative reviews have genuine and profound consequences. Moreover, it's a pretty competitive field. Many many years ago, I did these reviews anonymously. But it didn't take long before I came to appreciate that reviews of my own work fell into two categories: good, constructive reviews by people who signed their reviews and nonconstructive reviews by people who did them anonymously. At about the same time, for reasons now lost in the mists of time, I also came to appreciate that, while we may think we're being crystal clear in our writing, it is possible to be misunderstood, and if there is no way to check the meaning, the written review is worthless. Thus, I decided to sign all my reviews, and never regretted it. Moreover, in all those years, only once has someone whose work I reviewed negatively reacted badly. Most have gone out of their way to praise the constructiveness of my reviews even though I might have reviewed their work negatively.
Thus, my counter to your excellent point, that the best measure of character is what one does when no one is looking, is that one should also have the courage of one's convictions.
Judy