 Because they know Kamala can't win. I suppose because you have a bunch of disenfranchised voters who voted for Joe Biden, whose votes won't matter unless you do this. Nobody wants Biden anymore. I understand that. But you voted for it. You pledged it. Those people are pledged to vote for him. And you're going to just erase them all. Unless Joe Biden himself steps up and says, I can't do this anymore. All my delegates I pledge to candidate X, whoever that is.