Well it depends a bit when you pivot. I'm guessing most people pivot before actually coming out with their product, simply because they don't know what they really want and they have no idea how to do it either.

Pivoting is good when you're already out there with your idea and then understand that you need to adjust to your customers needs. It is not when you don't really know what to do and just experiment with other peoples money to find out what YOU want.