Yes, he hasn’t been much in the public eye lately, and it’s hard to see how a march like this is going to get him back in. His one supporter in the Senate, Jeff Merkley, cheerfully went over to Clinton soon after the last primaries; Elizabeth Warren, who never did endorse him, is clearly 100% in the Clinton camp and evidently drawing lots of progressives with her. The Clinton/Warren tag-team pick-on-Donald-Trump tour did a lot to push Sanders back into the shadows (Bernie, that could’ve been *you *up there), and I think Sanders made a serious error in terms of his own credibility when he chose not to take part in the gun control filibuster.
So, of course, his supporters are allowed to march, allowed to march for anything they please. Call it a March for Progressive Principles. Call it a Down with Wall Street March. But to associate it specifically with Senator Sanders, when it’s evident that many, many progressives have moved on, marginalizes it, makes it seem as though the progressive movement relies solely on Sanders for ideas/guidance/legitimacy/existence. Sorry, that’s not a movement I would care to support.
Note that the OP describes the rally as a rally for Bernie Sanders, not a rally for progressive ideals.
And given that the senator is clutching that towel as tightly as he can and refusing to listen as the fat lady sings (gotta mix those metaphors!), the whole thing sounds like an attempt to keep alive the notion that Sanders CAN and SHOULD be the nominee. Despite having lost the primaries. Having a rally “for Sanders” smacks of “Let’s try to overturn the will of the people, because we really very badly want Sanders to be president!” THAT’s what I mean when I ask why the OP hates democracy.