The point of using bitcoin is so that users are rewarded both for sharing content, and for hosting the content.
> What role does it play besides some sort of integrated pay to post and tipping system? Both of these things can be done without bitcoin -- and far simpler too.
Although the idea I sketched out is for a decentralized reddit, a centralized reddit that just integrated payments is also totally valid idea. Imagine if Changetip were integrated directly into reddit so that upvoting tipped people. That would still be really valuable and a lot of people might use such a thing. But it doesn't solve the other problem of what to do when the owners of the service have different ideals than the users. (Note that I actually worked with the guys at Chain.com to produce a proof-of-concept of something like this.)
> Just create an altcoin that you have more control over. But I guess that no one (you?) would benefit enough, because its not tied to bitcoin's value being inflated.
A new altcoin would not be as useful as bitcoin outside of the system. Using bitcoin makes karma as real as possible. Using an altcoin would just be annoying and a lot fewer people would want to use the system.