I think time has demonstrated that some form of (possibly itself centralized to some degree) incentive system can be important for a healthy decentralized ecosystem, but it doesn't necessarily have to be directly monetary: private trackers do pretty well with ratio systems, even through they're not wholly decentralized in the classical sense.

I think this has a slightly ironic benefit in practice: by paying out in-kind, as it were, you inherently filter for participants who actually are after the functionality provided by the distributed system and aren't just out to make a quick buck, which leads to a better true believer:huckster ratio. Reminds me of how capitalistic incentives don't always translate to good content: see cooking recipe / other SEO blogspam, or capeshit. Scene respect is the sort of in-kind pseudocurrency that, while not without its own flaws, ime incentivizes better art.