All of those claims were anecdotal stories, before they were tested. By definition. Then they were tested and the results of the tests indicate they do not to hold up to investigation. It's hard to imagine how one could address your objection to "anecdotal stories never hold up to investigation" except by gathering anecdotal claims and doing controlled experiments on them.
Big difference here. The tests that you are talking about are on people who claim REPRODUCIBLE abilities to produce paranormal phenomena.
In an anectdotal story (lets say a patient without any measureable brain activity claims he had a visit with his deceased sister and learned something he didn't know before); the claimant is not claiming anything reproducible for a skeptic to test.
These anectdotal stories are what skeptics try to dump into the never pan out category. This is an unjustified claim as 95% of the time we will never know with certainty.