Popper/Feynman/fallibilists/etc: Mistakes are very easy to make. In addition to imaginative conjectures, we need relentless criticism. If we don't have that criticism, we'll constantly be fooled by mistakes.
Others: Stop dismissing everything so easily. It's good enough. No one is going to be fooled unless they are an idiot. Imagination is more important than criticism. And anyway, the way to avoid mistakes is this: proven or supported ideas are not mistakes.