Interesting point, apparently no one knows where that image originated, or what it originally said.
I know EVE was in the original version I saw years back, and there seems to be some misattribution to XKCD (presumably due to the art style and humorous graphs?). Bonus points if anyone knows the POTBS reference offhand.
http://images.mmorpg.com/features/4577/images/LearningCurve....
https://m.reddit.com/r/AskReddit/comments/3m1ahz/which_games...
http://i.imgur.com/YzevDTs.png http://dwarffortresswiki.org/images/4/40/FunComic.png