https://www.rt.com/russia/578601-recap-putin-address-wagner-coup/ 

Putin is responsible for this, because he has let a conflict continue for 16 months that should have ended in one week.  But Putin wanted to avoid being labeled an aggressor and confined combat to the Russian Donbass.  He got the label regardless, and created a situation of an ever-widening war that he has been fighting with a private military group who are tired of the no-win situation Putin has created by his pretense that it is a "limited military operation."

I doubt Prigozhin intends a coup.  Most likely it is a protest against the Russian military brass. The generals don't like him, because he refuses to place himself and his forces under their command.  As the Wagner Group is the principal military force Russia has fighting in Donbass, it is stupid for the Russian generals to foster bad relations with the commander of the troops doing the fighting.  A question I have is whether Putin is being given honest briefings about Prigozhin's intent or, instead, briefings designed to settle the generals' score with Prigozhin.  For Putin it is just a problem that needs to go away, and he might fail to learn from it.

The way Putin has been conducting this conflict has never made any sense.  By refusing to use sufficient force to end the war, Putin has widened the war to the extent that Washington and NATO are involved, and he has apparently lost the confidence of the Wagner Group commander and, for all I know, the Wagner troops.