why would Google help a competitor like that, though?
The article mentions Google is heavily invested in it.
Google is safeguarding it's investment in SpaceX.
Maybe common investors want to sell stocks to retail
They are not. The amount of conspiracy in high ranked HN comments for AI companies is insane.
Google (Alphabet) owns 6% of SpaceX which they bought for $12B in 2015. They want to maximize the value of their investment.