someone people are needing to pay tax bills in the US. By selling off a losing commodity like bitcoin, they can pay the tax and get a write off for their losses for next year.
At least that's what I'm thinking, because that's the boat I'm in

That actually makes perfect sense. They have the funds to cover the money that they owe and, simultaneously, they can have a much smaller bill next year. That person might turn around and buy again in a couple days/weeks.