I think everyone here understands why Bernie supporters can be disappointed about Ellison losing. That's a natural reaction.
But the fact of the matter is that Perez is a strong progressive chairman. If Bernie had not endorsed Ellison, I'm betting some people would have thrown their support behind Perez! But because Bernie gave his input, it became a proxy battle. The popular former president obviously wants control of the party going forward so he convinces Perez jumps into the election, receiving an explicit endorsement from Biden (who also should not have endorsed).
I should add that this is the same former president who convinced Tom Perriello to run against Northam in the VA Gov primary, so Obama's support is clearly not a matter of "being establishment."
Responding to the news that Perez won and Ellison will be his Deputy by saying "I'm never voting for Democratic candidates again" or "This party is dead to me" means that all you have a shit about at the end of the day is Bernie's endorsement. You didn't care about policies, you cared that Bernie supported that person.
If people are going to riot about that, then they frankly aren't worth having in the party because they aren't reliable votes. Donald Trump is POTUS now and the Republicans control both the House and Senate and a majority of state governments. We have work to do and people to protect.
So, we understand why people can be disappointed that Ellison lost. I am, since he was who I wanted. But Perez is a fantastic choice and will be working closely with Ellison in the future, as they're clearly both friends. It's time to move on and if people want to continue to complain about the DNC being corrupt or rigged against Bernie even when Bernie and Ellison are both OK with the results, I really don't give a shit about those people. It's not worth acquiescing to them because they'll find something new to complain about if you do.