This statement is a product of your opinion rather than your experience; and of course everyone is entitled to their opinion. However, from a scientific perspective, I'm sure you would agree you cannot prove it is nonsense, all you can do is claim it is nonsense ... and bundling it with other negative examples is a bit of smoke and mirrors.
You're right - science can't prove negatives, on the whole. But that's not an argument to accept ANYTHING as true simply because science can't "disprove" it. The way it's supposed to work is that a person makes a claim, and the onus is on them to provide evidence which supports that claim. Once that evidence has mounted to a considerable breadth, it may be accepted as true beyond reasonable doubt.
When it comes to dowsing, we're at the stage where somebody has made the claim. We haven't yet moved to the stage where the claim has been supported by ANY evidence, let alone substantial enough evidence to by accepted as true beyond reasonable doubt. Not for lack of trying - sceptical scientists have actually given opportunities, at great cost, for dowsers to prove their claims, by providing well-controlled environments for them to do so. Nothing. It comes up trumps.
So yes, it's not scientifically proven that dowsing never works, but that lends it no credence whatsoever. That is NOT an excuse for believing it without question.
Conversely, having experienced dousing myself, where I was unable to physically stop a hazel twig from twisting out of my hands, I like others here can attest to it's reality, all be it anecdotally.
Like I said before, first hand experience of something is nowhere near a reliable account of it. Nowhere near. Human psychology is incredibly delicate, and easily tricked - nobody would deny that. A five year old can learn a magic trick that leaves grown adults baffled. There are webpages dedicated to pictures and movies which trick the human eye EVERY SINGLE TIME, even when the person is aware of the illusion and how it works, it doesn't stop the illusion's effectiveness. So, knowing that our perceptive systems are so easily tricked, why are people so willing to rely on them to back up absolutely extraordinary claims about the universe?
Can I suggest that at some point, some scientist somewhere, made an anecdotal observation they could not explain .... I think you can see where I'm going with this .... there are plenty of examples of where science has made mistakes, it's part of the process .... maybe dismissing Dowsing is such an oversight?
Dowsing has not been dismissed or discarded without test. It's not as if somebody proposed dowsing, and science went "nah, doesn't sound likely, just forget it". Scientists, despite their sceptisim, have spent TONNE of money and time looking into dowsing, giving it the best possible opportunity to present itself as authentic, and it simply hasn't worked. Study after study shows it to be false. James Randi has a million dollar prize available to anybody who can provide evidence for their superstitious claims under controlled conditions, no dowser, no tarot reader, no psychic, no spoon-bender, no homeopath and no flat-earther has ever taken the prize.
There are PLENTY of opportunities to provide evidence for dowsing. All a dowser has to do is write a scientific on the paper on the topic providing repeatable, testable experimental data, and publish it. It would turn science on its head, and I love it when science gets turned on its head because it means we're improving our understanding of the universe. I would LOVE for some breakthrough like this to occur, but it hasn't, and it very likely won't be.
I don't think it's valid to accuse me, or other scientists, of dismissing the claims out of hand.