I am still very much anti-capitalist. I'm a socialist, if anything, and not "democratic socialist" like Bernie. He's not actually socialist enough for me. I don't believe that continuing with our corporate controlled, two party capitalist democracy will ever result in true justice for the people or liberation for the oppressed.
I do believe in the idea of working within the system for now. I vote in every election in an attempt to hopefully make things a little better for some people (and possibly to give myself some sense of control). But I absolutely understand people who have been utterly failed by our democracy being so disenchanted that they refuse to vote.
The Black Lives Matter movement explains this quite well in a brief interview about their decision not to endorse any candidates for president this year. Black Lives Matter organizer Melina Abdullah explained that they'd rather put their time and energy into real revolution, of which electing Bernie is not:
We know that the revolution won’t come at the ballot box and the revolution won’t be televised. The revolution will be on the ground, when the people rise up and demand something better, something more imaginative and something more visionary.
I highly recommend reading the entire interview, which is not long.
"We Are Pushing Real Revolution": Black Lives Matter on Why They Don't Have Faith in Any Candidate