Shooting street with a tele is unthinkable to me. It completely ruins what street photography is about; blending in with the scene and showing the environment of the subject. The flat photos people get by shooting street with a tele throw me off too, it becomes a registration of some individual. There's no sense of 'street photography' at all, the feeling is gone.
With a short lens, you can easily get it out of your pocket and take the photo. With a long lens, you have to lift the whole thing up (A combination like this would be at least 2kg, vs 500grams with a short lens), frame, reduce shake, hold your breath, shoot, and hope for the best.
I dont know if this has been mentioned before in this thread, but Henri Cartier Bresson would be able to take the photo in under a second. I have yet to discover someone that can do this with a tele.