It seems to me, and I could have misread, that the biggest problem with the examples of currency systems in the article is that the 'pooled' currencies are unquestionably accepted by participants. Take that guarantee away, and someone could design a reputation currency where participants could reject payments from disreputable participants. In which case accumulation of units does not imply the long-term ability to use them; instead, there will be a long-term incentive for participants to maintain a good reputation.
See this overview of a counter-example to the article's point, a reputation currency system without a central issuer: https://tatag.cc/ui/home-about. (Disclaimer: I'm the developer of the linked site.)