I might have heard it mentioned, but I hadn't seen the details. The problem is the fixed 5% demurrage rate. Having a fixed rate fixes no economic distortions whatsoever, since if (say) the value of a bitcoin grew by a constant 5% a year price setters could costlessly index to this known growth rate. The aim ought to be to use demurrage/interest to remove unpredictable fluctuations, not predictable trends.

The 80% distribution to a foundation also seems troubling.