The point is that you're testing something for which you aren't the target user. Champagne is a bad example because champagne manufacturers most certainly thems

The point is that you're testing something for which you aren't the target user. Champagne is a bad example because champagne manufacturers most certainly themselves imbibe in their own product, in fact they're probably connoisseurs. It's a very different development process to make a product for which you aren't a target customer.