I disagree with some of these. I'm as Bernie as the next guy, but even an idiot could see appointing Ellison would be a handicap to the Democratic brand. Obama was not Muslim, and still had a hard time with just the insinuation. As with Clinton, Ellison's thoroughly pre-tarred, pre-feathered. Hurting him in this DNC election took a mere flick of a pinky finger on the part of the howling classes. I see some right-wing orgs already calling the Perez/Ellison DNC "The La Raza/Muslim Brotherhood coalition." That likely plays very well to the fears in the Rust Belt and Deep South.
But there's worse among our allies. I find grassroots progressives with the impression that Ellison was a Sanders campaign strategist (Outrage: "They denied us, AGAIN!"). He was not. Bernie merely endorsed him, long before Perez got in the game.
So take a chill pill. If you split off, attack your own brand, you weaken and destroy the one best chance we've got. The DNC must be changed from within, not by balloted decapitation. It needs a (not so) gentle systemic purge. Fellow citizens are going to need our help and support; can't be effective doing that, spending all day railing at every dust speck the White House and Congress generate.
Politics seems fast, but in reality moves desperately slowly. Get involved, open your big fat traps where they count (and I include myself in this).