Humans are just amazing at refusing to acknowledge existence of evidence.

And those humans would be the reflectively inconsistent ones.

It's true that humans cut themselves from a significant good this way, but upside is worth it.

Not as judged from the standpoint of reflective equilibrium.

Any idea what it would be? It makes little sense to manufacture a few big paperclips if you can just as easily manufacture a lot more tiny paperclips if they're just as good.

I already make small paperclips in preference to larger ones (up to the limit of clippiambiguity).