Source: I was using mapping tools before Google Maps came to market.

So when a book store giving away books for free puts another book store out of business, that second book store didn't have a great product?

Unless the end-game for the 2nd store is to price out every single book store, then obtain a monopoly. But then anti-monopoly laws should come into place.

But if the end-game for the 2nd store is to subsidize their cost via a different business - then it's the same as a newspaper using classifieds to subsidize their subscription business. You can't then argue that another newspaper that charge for subscriptions goes out of business is unfair.