Cruise was being operated as a separate company though. As a default, GM could have just not done anything and let Cruise operate as if it were independent. Any synergies (personnel, manufacturing expertise, etc) would have just been a bonus. And if they didn't want the financial exposure, they could have spun it out again.

Instead they chopped it up for spare parts, specifically, sending some Cruise personnel to work on deadend GM driver assistance tech and firing the rest. Baffling.