Do you really think that there wouldn’t be similar examples where those disbelievers were right? Picking examples about times when disbelievers were wrong doesn’t prove in any way that disbelievers are always wrong or that this time they are wrong.
For instance, looking at the street and pointing to couple of BMWs doesn’t prove that all cars are BMWs — or even that the next car showing up is a BMW. It just shows that at least some portion of the cars are BMWs.
Furthermore, the issue in the proof that you give is that it tries to show that disbelievers have historically been wrong — and that is easy to deny just by giving a counter-example. And here’s one: Norden bombsight. It was supposed to revolutionise bombing during WW2 and huge resources were used to develop it and to keep it as a secret. However, the results it got were not much better than what was possible without it.
With cherry-pricked examples, you can just prove that something is possible; not that something is certain or that something is likely.