Totally agree that sports make a city.
Reason being that pro sports is largely a spectacle. Cities often define themselves (well the non-sleepy ones anyways) by their ability to host the spectacular.
Pro sports is unique in that it offers the spectacular on a predictable, scheduled, frequent basis. People want to be there, they want to be involved, and they want to experience it, and best of all, it happens every Sunday.
I lived in Ottawa my whole life growing up, and that city is often considered the most boring major city in Canada. Why? Not enough 'spectacular'. The only time I remember being even vaguely proud from a civic perspective was when the Senators made it to the 07 final.
Pro sports bring pride, prestige, excitement, and most of all consistent 'spectacular' to a city.
It forces people from other places to think about your city. No offence, but I literally never give Hamilton a thought outside of when the Tiger-Cats are playing..and then I think about it a lot. I would probably never in a million years visit Hamilton willingly...except wait, they have that CFL franchise? Sweet maybe I'll pop in one day and check it out, go to a game, buy some stuff.