It seems like this incident took place near teddy intersection at approx. 7000 msl? That’s just a really bad place flying if you’re not talking to ATC, with or without a transponder. Teddy is major point on the arrival and anyone that’s flown into ORD has heard of it.
The flight aware track is deceiving because the jet does a few turns over Janesville at 10000msl but that’s not where the conflict took place. It was SE of JVL at 7000msl when the jet had to climb to miss an aircraft..

As glider pilots we really need to know where the jet traffic is and not go there unless you're in contact with ATC. Look up all the major airports you fly near on Airnav.com, read about the runways, and especially the STAR arrivals, also frequencies, and phone numbers are helpful. You can download free copies of the STARS. Knowing what runways they are using based on winds the day of your flight can help.
Then on your flights, if the lift takes you near a busy intersection at the altitude used, call ATC. If you’re well below the traffic, maybe just listen? However, know that if you have a transponder and don’t call, you are causing a lot of chatter on a busy frequency. They will all be trying to figure out what you’re doing.