Honestly, because I want to eventually publish some stuff online.
So for people to buy something, they would need to know what they are getting. So this is to establish that. Along the way a lot of stuff will be made available here anyway for free. So it isn't just for advertising.
What I plan to publish at some point are story modules, roleplaying adventures/ supplements, story games etc. We will have to see where things end up.
So one thing is why. The answer is because I like telling stories and it is more fun when other people can enjoy them.