Employees who love their own product are a cancer that must be treated. Complacency with a product necessarily leads to a dangerous inability to find ways to improve upon it.

I do speak from long experience, here. This isn't a crazy idea I read out of a dogfooding blog entry.

I don't want employees who love my product, I want employees who are competent. this example is telling in that although the prospective employee clearly wants the job she is also clearly not a particularly talented designer.