Reading this story and related comments, I'm struck folks have lost the history around dogfooding. From what I understand the term really picked up from Paul Maritz.
The saying was - "if you're not eating your own dogfood, you're smoking your own dope."
Very basic idea: is your product good enough that you would use it / consume it for your own needs and purposes? No? Then you are deluding yourself if you think you have a good product.
Simple as that.