A not-insignificant portion of the people who are pushing Tara Reade to the fore are actually people who were in the Bernie camp. A lot of them are unsurprisingly incredibly pissed off at their loser losing for the second time in a row, and they're venting that anger by driving this home against the Democrats in any way they can find.
I'm just enjoying it because this is the last scrap of anything resembling principals that the mainstream Left even had. They completely abandoned their anti-Big Business crusade when Occupy Wall Street collapsed and most of them defend mega-corporations now (It's a private company etc), they don't care about the environment anymore because they just scream Climate Change which means nothing, they've given up on pretending they're not racist because not only do most of them fucking detest white people, but if a minority crosses the line they'll straight-up start tossing racial slurs at them, they don't give a rat's ass about freedom because they openly embrace authoritarianism at the drop of a hat, and now Believe All Women and Me Too has just been thrown under a bus, all for the sake of politics.
Every decision they make is politically-driven. There's no standard, there's no principal, there's no morals, it's all politics and emotion all the way to the baseboards. Even if Joe Biden is completely innocent it doesn't even fucking matter anymore because so many of them openly declared that they'd vote for him even though they believe he's literally raped someone.