I think the point is that it's something to build on in 2018 and if democrats take back the reins of power in 2020.Even if Bernie's bill passed Trump would veto it and it would die.
Also this is a movement of the Overton window. The goal is in the long term making the discussion of universal healthcare normal. Right now, and I think it's changed drastically just over the last year, the conservative no government intervention is best is leading the conversation. That needs to change.
I don't expect this to pass in a republican dominated congress and president. People aren't stupid. But this is setting up an issue that voters will consider as a litmus test for future candidate and future elections and if it's 2024 before we even sniff such a system , you can guarantee the road started at this point to get to that point down the road.
We discussed government revamps to healthcare since Johnson. There was another spate of discussion during the Clinton and bush era before we ended up with ACA.