I believe you're making a false comparison. None of the market participants have a way to express their preference for a decentralized network except by defining Bitcoin to be one though the rules of the system. Absent that someone who doesn't care and just wants to maximize their short term income can turn the decentralization knob all the way down (as we've seen with the enormous amount of centralization in mining pools) and maximize their income-- regardless of what the owners of bitcoins or the people making the transactions prefer. You could just as well argue that miners should be able to freely print more Bitcoins without limit and magically if the invisible pink hand decides it doesn't want inflation it will somehow market-prevent it (in a way that doesn't involve just defining it out of the system).