But you are right on one thing. Capitalism is no longer doable. What we have is crony capitalism, and Citizen's United is essentially the constitution of crony capitalism. But crony capitalism is 1) very inefficient -- by the standards of pro-capitalism neoclassical economics! See Stiglitz' The Price of Inequality on that; 2) also increasingly unstable as inequality increases. (Stiglitz, who believes that capitalism can and should be saved, has no solution. Keynesian economics can trim the sails -- but when the mainmast is overboard, there are no sails to trim.)
But on your other point -- only half right. Soviet-type socialism is not doable, I agree -- except perhaps as a temporary emergency measure. But that has never been the only plan for socialism. A socialism based on decentralized worker-control and planning from the bottom up can give us a future worth having.
As a Fabian socialist, my hope is that the self-destruction of capitalism can be foreseen and avoided by building socialism through democratic processes. I admit my hopes on that score are less than they were. The alternative -- self-destructive collapse of capitalism followed by revolution "like kicking in a rotten door" -- would mean a terrible life for our children, though our grandchildren could reap the benefits. For our children's sake, we need to get out there and change minds, despite the obstacles created by Citizens United and all the other advantages that the billionaire class has. And make no mistake -- I am old enough to remember the eighties and nineties -- neoliberalism does not have the momentum it had. People are looking for some answers. Don't give up.