I was always confused and intrigued what was going on behind the scenes when Tesla was so obviously and publicly rejected by the Biden administration in that manner.

Musk was even then a polarising figure, but given Tesla was arguably more “American” than even the self-proclaimed traditional American car companies, it seemed a weird, self-defeating, perhaps emotional, position for the administration to take.

Tesla not being unionized was the main guess I heard about it at the time. The legacy auto industry has a history of outsized political influence leading to many dumb decisions on politician's part from an administrative success perspective.

I don't know either really, I'm just reporting remembered second-hand sources.