I don't understand the logic here. When the putsch occured and then ignomously fizzled out, I saw Putin as weak for letting Pringles walk out with a (relative) slap on the wrist. Taking Prigo out of the picture was overdue. Obviously, anyone would feel threatened by an semi-autonomous mercenary army, so removing its leadership and breaking it up is just a rational course of action that probably should have been done sooner from that POV