I was using the classic idea of the flying car as an example of a thing that has been out of reach as an as a product for normal people and may not actually be successful if it were to really be sold.

Replace flying car with whatever example you want.

To put it in a different way, you could be so busy figuring out how to do it that you don’t figure out that a business case doesn’t actually exist.

I wasn’t trying to comment on any of Musk‘s other companies specifically. Only that we don’t know if making robots will actually make money.