Earlier quoted context omitted.
The brevity is what makes Twitter distinct from everything else.
Funny, I thought the reason people should use a service is its worth, not auxiliary novelties. If I make a pitch to somebody, do you think I should rest assured that they'll go for it if I word it in the following way, "Now I know that by almost all metrics this kind of behavior is bad, but we did some looking into what other people are doing, and it's unique ."?
And which metrics show that limiting updates to 140 characters is bad behavior? URL shortening sucks, for sure, but that doesn't mean the limit on prose isn't useful or attractive to users.