Politico recently ran a story critical of Sanders that was headlined "Sanders had big ideas but little impact on Capitol Hill" that was a classic Washington view of life. No matter that the current Congress is one of the most disliked in history, you're still meant to play the game and get your score by how well you do it the way those who hate change want it to be done.
In fact, change doesn't work like that. Every major change in American politics has required years of failure by its advocates. In 1848, for example, the first women's conference was held in Seneca Falls. Only two of the women present lived long enough to vote. When the suffrage movement got underway, if Politico had been around, it might have run a story headed, "Woman advocates have had little impact on politics."
What is important about the Sanders campaign is that it is the most hopeful sign of change underway in decades and, win or lose the election, America won't be the same as a result of it.