You chose to make your photograph free. John Mueller chose to charge for his work. The point is that the creator gets to charge for his work if he wants. If the price is too high, he doesn't make money. If the price is too low, he doesn't maximize revenue. But it is his choice to make.
Keep in mind that we, as a society, decided to give them that choice to make. It was believed to be in the best interests of everyone to allow them those freedoms.
However, we as a collective, are welcome to change our minds if that freedom is proving to not be beneficial to society.
This is the problem we are facing today. More and more are changing their minds on the matter. They are not seeing the social value.
You chose to make your photograph free. John Mueller chose to charge for his work. The point is that the creator gets to charge for his work if he wants. If the price is too high, he doesn't make money. If the price is too low, he doesn't maximize revenue. But it is his choice to make.