I still say that it's not a waste of money. It's unfortunate that people can't afford games sometimes, I definitely can't most times and only buy one once in a while when I have a little bit to spare on things after bills and groceries, but to say that supporting somebody who created something you enjoy is a waste of money is immature and ignorant.
It's like walking into a high-class restaurant and complaining to the chefs that you can't afford the fresh lobster, so you deserve to have it for free. Maybe you do deserve that lobster, it sucks that you and I can't afford it, but the world doesn't work that way and those chefs still need their paychecks so that they can live comfortably and continue to cook more lobsters.
There's no argument to be had about paying somebody for the work that they do, it's common decency. It's honestly very nice of the developer to even offer a free version of the game they worked so hard on, which makes what you said even more insulting to them.