I don't want to challenge capitalism - competition drives innovation, and the need to survive and to make a better life for oneself is at the core of that. However, we need to admit that not all people are driven by this, and in our world (at least in the United States) it's not about survival in terms of life and death and hasn't been for some time.
The people on our streets are not there because they deserve to be, neither are many of the people in the boardrooms. Today, there's a disparity between the have and have nots and it has less to do with capitalism than the reality of growth which Piketty outlines really well in his book that's definitely changed the way that I look at it. It's hard to see value in supporting the status quo when it's only going to return 1-2% year after year - especially after an excessively long period of unprecedented growth due to the devastation and rebuilding through the 20th century. However, this results in a lot of the wrong things being valued in my opinion.
I feel like we're at a pivotal point in human history. We're at income disparity levels second only to countries scourged by ISIS, we're at wealth concentrations comparable to Europe pre-world war one. Marginal income increases have little to do with marginal productivity increases of either companies or employees. I feel like the fundamental definition of value needs to be re-evaluated.
I really think that the nature of capital/wealth have really changed. When cost of living dominates anyone's ability to be a productive member of society, that's when we should reconsider how to go about either distribution of wealth that's leading to that (that hardly ever works) or instead how we quantify and define wealth. Shifting this balance in favor of what we as a society value, I think is the best way to start to really change things.