While on some level "standards" are decided after the fact in the Open Source community, but they are rooted in conscious decisions. No one said that Jim Fulton had special authority over Nevow, Python web programming, or anything -- the informal authority he has was gained through his action and involvement, and leveraging the authority from a popular framework (Zope). And even in the presence of Zope Corp, he still doesn't get a pass when it comes to authority in that community. "Authority" in all these cases still only means that people choose to listen to him, not that he can actually make people do much (at least outside of Zope Corp).
In turn he chooses things consciously and strategically. Many people in the community do this -- they choose something, either to follow the opinions of others, to start out on their own, to become part of some project -- based on conscious decisions that include their imagination -- what they think will happen with projects, how they personally feel invested or alienated from a project, how they imagine a design fitting into their unknown future developments. Not all programmers do this -- but almost all the ones that matter do. Developer-users -- people who just download packages and use them in their isolated environments -- have very little effect on the code or community. Imaginative programmers are what make things happen, and that's who I'm trying to appeal to with most of what I write on this blog, because sometimes code alone isn't enough to spark someone's imagination. And sometimes I don't have code to hawk anyway ;)
In conclusion, because I don't think I've made my point entirely clear yet: on one level you can look at the community and its decisions as an organic process of evolution. And seeing that you can think that conscious decisions and strategies don't matter, that standards can't mean much, that the best man will always win in time. But the other side is that the community is made up entirely of individuals -- it seems organic because there are no authoritative institutions, no authoritative decisions outside of what an individual chooses for him or herself. But individuals make decisions for very conscious and personal reasons, and though it's a different process to appeal to a community of many individuals, it's still worth doing.