He wasn’t proposing to make a documentary about himself. Someone else was proposing to make a documentary about him. And (as DanielLC quite rightly says) the perfectly obvious purpose of this is that some people might find it interesting and want to watch it. Indeed, presumably about $10k worth of people did anticipate finding it interesting and wanting to watch it, since the project did get some backers.
how is making a documentary about yourself not just contributing to your own glory?
He wasn’t proposing to make a documentary about himself. Someone else was proposing to make a documentary about him. And (as DanielLC quite rightly says) the perfectly obvious purpose of this is that some people might find it interesting and want to watch it. Indeed, presumably about $10k worth of people did anticipate finding it interesting and wanting to watch it, since the project did get some backers.
Someone might want to watch it. If so, it’s contributing to their entertainment.