I can't understand why. He just defecated in his own punch bowl. Basically he just shut down Washington DC and the entire legislative agenda. Any legislative agenda.
From McConnell's point of view, small price to pay for sticking it to Bannon and Trump.
And they have operated as the swamp any different than that in how many years? It is never about fixing things, it is about keeping the wound festering or making new ones as they feel they are the only ones to apply the dressings, and want the repeat business.
You and I want a whole new medical staff if you will...
My guess is he is a lazy SOB, drawing a paycheck and is more interested chasing male pages than passing legislation.