There's no doubt that a lot of free sites were put there because it gave something to the creator. Maybe it gave them an ego boost, maybe they felt a sense of accomplishment for creating something that became popular, or they got warm fuzzies from sharing something with others that they have a passion for.

Free internet sites that don't exploit users don't require pure altruism. I assume nobody is paying you to contribute to this site, and I assure you that I'm not being paid for it, yet here we are. Sharing and offering something without hurting anyone or taking from them.