Acting on emotion?
He apparently stockpiled weapons and ammo for 2 months. Few weeks ago captured a russion army officer and forced him to admit that russian army attack Wagnerites. After being released the officer denied it, ofcourse. He also staged a scene of an attack on wagner camp to use it as a justification. All of this sounds very calculated and premeditated to discredit russian army and MOD.
He was careful to never accuse Putin, possibly out of loyalty? But it looks to me, that goal was never to remove Putin, but either preserve himself (as Wagner was to be incorporated in MOD on 1st July) or assume command of military. I think it was a coup, but against Shoigu. He was probably surprised to be called a traitor by Putin (however Putin never named him in his speech, apparantly). The dice was cast, but once he got his off ramp, he took it. However, the question remains, what is the deal that Lukashenko brokered.
If Shoigu is removed, then Prigozhin has won, temporarily at least. However, he will have to look back constantly, as Putin will look to dispose of him.