The core of the 2015 team was Price, Buehrle, Stro, Edwin, JD Tulo, Martin and Bautista. Between retirements, massive declines in ability, and in the case of Price, huge free agent deals, the core was gutted organically because it was only built to be temporary.
As Hurk said, the best thing Shatkins has done is avoided the temptation to keep that ageing group together.