Please understand that this is someone's livelihood. Any job deserves payment, especially work that people have clearly put lots of time and effort into (such as this.) It's like asking a chef if you have to pay for the steak you ordered.
Gaming is a luxury, not an essential part of life. If this game is paid it will not have any real impact on you, but it will on the creator. It is their choice if the game is paid or not.