Zero at $5 was never profitable. I think it was reported that they consulted Eric Schmidt and followed his advice to sell the core hardware at loss and recoup from accessories and bundle sales, which didn't suit their business, but did it anyway. This was why it was limited to 1 per customer and also because Pi Zero and Pico models have a more overpriced/appropriately-priced "WH" variants with no purchase limits.

I wonder if he uses this model for his current killer drone business.