Well, I would qualify it -- make any exposition as brief as possible, but no briefer. I think elegance is a better word. It applies to the way you choose words in structuring sentences so that you don't need to say the same thing in twenty words IF it can be said as well or better in ten.

Brevity that detracts from communication is a sheer waste of brevity.
But that is not what is meant when writing advisors urge brevity. They are battling excess, the kind of long-windedness that comes from a paucity of good thinking.

"Screw brevity." is a wonderful, ironic, and elegant sentence. Brava.

A