Sounds like you agree perfectly.
The office market - for old economy businesses like finance, manufacturing, retail, etc has gradually shifted westward to be closer to the Metra stations, where the suburb-dwelling executives step off the train. River North has boomed with new economy stuff like tech and creative because it is convenient to the Brown/Red Line and North Side bus lines, which urban-dwelling creatives ride to work.
Google's move to the West Side is a big deal - it's not convenient to any transportation options. It's on the L network, but everybody who lives on the North Side would need to transfer to the Green Line, and rail-rail transfers are particularly sucky in Chicago. The Halsted bus is also an option, but not a very fast or convenient one. Conventional wisdom says Google employees will respond by driving, but Sterling Bay is not providing much parking and street parking is not a great option. I'm betting bicycling will be hugely popular for these workers.