Eve would be a data point supporting this. I had some adrenaline rushes playing Eve, but I also could use it as a sleep aid, depending on precisely what I was doing.

I think that one of the problems is a poor conception of what it means for players to create content. The most compelling content for me in Eve was simply the most exciting stuff that happened during nullsec alliance PvP.

In the end it's different largely because they are not trying to be a 'successful' company, instead of kind of a profitable hobby.

This also fits with my current goals.