Good thing that isn't the argument, isn't it?

Even a century ago they had good reasons to think it was possible. Medicine was getting a lot better VERY quickly. They turned out to be wrong, but I wouldn't say that they were utterly crazy for thinking that they could keep finding low-hanging fruit long enough to work out the underpinnings and solve the problem.

Now, we can see a lot more clearly how far we are from the 'finish line'.