A poll taken last spring reveals that a majority of young people do not support capitalism, according to a story in the Washington Post, and fully one third of them favor socialism.
It's not clear whether their disenchantment is a result of a principled opposition to market economies, a failure to understand what capitalism is, or a consequence of the young feeling frustrated at the shrinking job market.
In any case, it seems clear that what many of the people surveyed are discounting is that the free market has brought more well-being to more people in more parts of the world than any other economic system in history. Even the world's poor are much better off as recipients of aid from countries where there's an abundance of wealth created by dynamic economies than they would be had those economies not been the engines of wealth creation they've heretofore been.
As this video shows, pace Bernie's supporters, socialism is neither a just nor a desirable alternative. The video addresses one aspect of the socialism/capitalism distinction, i.e. taxation, but it's also a good general illustration of socialist and capitalist approaches: