Strava is awesome!!!
People who try to rationalize that it encourages dangerous riding are just jealous because their segment times suck. And that old hat about pinning on a number and racing in circles around the block is the litmus has no idea how to really ride.
How hard is it to ride fast when everybody is going the same way at the same time? It takes real skill to command presence and respect on the open road with a 30lb. bag. Commuters rule.