Not plausible:

Humans are just amazing at refusing to acknowledge existence of evidence. Try throwing some evidence of faith healing or homeopathy at an average lesswronger, and see how they come with refusal to acknowledge its existence before even looking at data (or how they recently reacted to peer-reviewed statistically significant results showing precognition - it passed all scientific standards, and yet everyone still refused it without really looking at data). Every human seems to have some basic patterns of information they automatically ignore. Not believing offers from blackmailers and automatically thinking they'd do what they threat anyway is one of such common filters.

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

minimum mass of a true paperclip

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.