After launching the first version of Facebook for a few thousand users, we would discuss how this should be built for the world. It wasn't even a thought that maybe it could be us. We always thought it would be someone else doing it.
People love photos. Photos originally weren't that big a part of the idea for Facebook, but we just found that people really like them, so we built out this functionality.
I mostly built stuff that I liked.
A guy who makes a new chair doesn't owe money to everyone who ever built a chair.