At least Mike went out with dignity, like a man.
Reminds me of the movie The Shootist.
The John Wayne character tells Ron Howard that you might be the best trigger man in the world but it will be some clumsy lucky punk who will get you in the end.
Walt's actions were more of passion, of anger at being disrespected, of being called the greedy arrogant screw up that he has become.
Mike told him the truth and implied what Walt fears, that he is not the great man of intellect, the great man of family, the great provider. Walt is just going to get his family killed before he dies, and corrupt the rest of the people around him as well...how many times has he dragged people down his black hole of self destruction? Mike wanted out, Saul wanted out, Jesse, Skyler, and yet Walt keeps spitting in the wind, the futility of feeling that he is important and a great man of action.
I'm impressed by the sly way the writers have achieved all this.