You are, in essence, asking us to overturn almost the entire concept of scientific analysis. If we were to follow your lead we could forget about probabilities and likelihoods, we could forget about causality. Just about the only link between the water ingress and the fin seperation is they both occurred in roughly the same part of the aircraft. Unfortunately proximity doesn't really count when it comes to attributing blame, there's got to be something else, otherwise we can falsely attribute all manner of failures in one component to the failure of something else simply because it's close by.
Just because you have seen a repeated incidences of water ingress doesn't mean it played a part in an incident when the PF managed to impose loads way beyond the design failure level (and remember that the design failure level is typically 50% greater than that which should ever experience in normal flight). If you bend the aircraft hard enough it'll always break, and as a professional pilot I know that if I kick full opposing rudder movements into the system on my aircraft then I am probably going to break something, and we don't even have a water ingress problem.
Perhaps we do all deserve each other, but I'm willing to take the risk that the experts are actually correct and not corrupt and in the pocket of the government and Airbus Industrie. I'm sufficently confident that the NTSB (but not the FAA) know what they are doing. If they say that water ingress was not the cause of the accident and mishandling of the aircraft was then that sits comfortably with me, and probably most of the scientific community worldwide.