I hear what you are saying. Perhaps one function is to provide an outlet, some people hold on to their story for years, perhaps half a lifetime, unable to confide in those people closest to themselves. Sharing the experience like this might act as a release, allowing some of the frustration to be let go. Similarly, it may help others, regardless of whether they contribute to the collection, who have undergone a similar experience. I suppose what I'm suggesting is that this is providing a service not for the sceptics or disinterested bystanders, but for experiencers themselves, to make the open discussion of such topics less of a taboo. Though we freely ramble on about such things on this and other forums, it may not be so easy to do so in everyday life, where there is still some stigma attached to discussing these ideas.
Similarly, people probably feel reluctant to discuss reincarnation and expect to be taken seriously, there is a long way to go in gaining tolerance so these things may be discussed openly.