The nice thing about not having one dominant industry is that the entire local economy is more stable and better able to take shocks to the system. (I've lived in NYC and Silicon Valley and both felt like boom/bust kind of places to live. I now live in Chicago.)
This is a weird expectation. Why does a city have to be "the best" at something? Seattle isn't the best place for software but I'd still choose it over SF any day. Chicago has plenty of industry.