I am the author of the map. Sure, I will take population into account in the next revision. My main focus when creating this was to discover less touristy places, so I did not pay much attention to cities.
I am the author of the Touristiness Map, and I just added a "Interesting Remote Places" map where I take in population data from geonames.org. It is on the same webpage as the Touristiness Map: http://www.bluemoon.ee/~ahti/touristiness-map/
I swear I picked the name before I saw your post :P