What do you mean, it is released to the public. Anybody can buy it, there's no exclusivity.
So you don't mean "public", you mean "free". Game developers need to eat too, they need to pay bills. Getting your name out there only helps if everyone pays a little bit. Free is good up to a point, to give people a taste of what they'll be buying, but if no one buys then you've put in a lot of time and effort for no return. Which some people are fine with, but not everyone can afford.