Why not? Keith is one of the premier defenders of this generation. Teams that have struggled to develop a culture or a defensive corps should be interested in his experience alone. He's the type of player you bring in for two years and then retire him the coaching or development staff to benefit your org for years to come.
He is absolutely NOT a premier defender of this generation. The previous one, yes. Not this one. His underlying numbers have been bad for a while now and he’s a big reason why Chicago has been one of the worst defensive teams in the league the last few seasons. That’s not a guy you bring in to “build a culture.”