makes sense. but then, in addition to normal distribution, max users (set to 12M here) is also a huge assumption, no?... guess I'm just trying to squeeze out what is the truly speculative part of the map, and what are the (simplifying) assumptions I can, more or less, subscribe to.
i think its not his intention to speculate about a maximum amount of users. with a very high amount of users the average will converge towards zero while the price goes to infinity.
this is more a analysis of market capitalization than price speculation. however you can guess the number of users and average for the future and the map shows you what the price would be in that case (without consideration of new btcs mined).
thats my interpretation.