The Quantum Exchange being in South Side occured becuase it's tied to Argonne, Fermilab, and by extension UChicago.
Once you climb high enough the ladder everyone basically has the exact same interests, especially in cities like Chicago.
It's the same way Penny (JB's sister and former Secretary of Commerce under Obama) and Ken donate oodles to Harvard because it is their undergrad alma mater (eg. Pritzker Commons, Pritzker Hall, Kenneth C. Griffin Graduate School of Arts and Sciences).
Also, Ken couldn't control Rauner given that Rauner was equally wealthy (he founded GTCR and is good friends with Carl Thoma of Thoma Bravo fame).
Pritzker and Rauner is basically two sides of the same coin where both were essentially retired but in the same circles and decided to compete because of personal ambition.