I think a lot of people confuse conciseness with shrillness.

Nearly right, but I think they confuse confuse articulate clarity with shrillness. We are all accustomed to listening to something like this: "Er, basically, what I would want to say is, um, at the end of the day, er, basically . . . " Then, when somebody like Sam Harris or Christopher Hitchens stands up and speaks, the very fact they go straight to the point, are fluent, articulate and clear, is interpreted as threatening. It is regrettable but true. Speaking in well-formed sentences, so that your meaning is clear, should be welcomed, but it is actually heard as a threat. I suspect that this is part of the reason why some people voted for G W Bush (who can't string an English sentence together) and the same people hate Obama (who can).

The threat I am talking about is felt by good plain folks, reg'lar guys, people who don't like intellectuals. P B Medawar was making a related point about people who purport to admire intellectuals, when he called attention to a tendency to mistake obscurity for profundity, and therefore to find clarity not threatening but shallow (relevant quotations from Medawar are in the Oxford Book of Modern Science Writing). Somebody recently told me she had met a philosopher at a party, and confessed to him that she had found his latest book very difficult to understand. "Oh thank you", he gushed, obviously delighted by the compliment.

Perhaps a third related point, different again, is the understandable tendency to recoil when we hear, at a party, say, somebody with a loud voice, obviously revelling in being articulate and well-read – somewhat as one recoils from those who preen themselves on being good looking. As an old girlfriend of mine said, in a wonderful phrase from her native New Zealand, "He thinks he's Christmas on a stick."

Richard