I read "The tragedy of the commons" in grad school.  It seemed like received wisdom to me.  I believe Hardin's point on the fate of the unregulated commons is not in dispute and that it is indeed a tragedy.  I don't think Hardin was in favor of the enclosure movement in England, the slow strangulation of the commons through privitazation by the nobility and landed gentry in the 18th? century.  I though of Hardin as one who truly mourned the loss of the commons and was trying to warn us so that this fate could be averted.  Preservation of the commons or an ecosystem required dealing with it on a macro level as a whole. This may involve regulation by governmental or supra-national agencies but it certainly requires mamagement by groups who will frame management of the commons in terms of the effect on the group instead of the effect on individuals.
Hardin is to me like Rachel Carson and Aldo Leopold, one of the early prophets of what we need to to do to preserve that which we have in common, and not as some have argued an opponent of the commons itself.