> there's no particular reason the free market can't provide such a service, but there's no guarantee that it will.
Still, I stand by my assertion that, in general, if such a service is legitimately valued and necessary, a provider will emerge. No, a free market does not guarantee an optimal outcome for every individual, not does it guarantee that well get what we wish for. But free markets are still generally better than non-free ones. Pointing out that there are pathologies in full fledged laissez-faire doesn't count for much, unless one contends - and can prove - that (one or more of) the other options has no pathologies of it's own.
sure there is. here's a bunch of reasons: http://en.wikipedia.org/wiki/Market_failure