I'm not even claiming that it works in MMOGs (consistently at least). It was pointed out to me that it does happen in some cases, so I commented that if it did happen here it would be good for investors.
I'd also note that it is very speculative at this point what will build a user base that is significantly above zero (on the scale of successful online social platforms) as well as what would keep such a user base happy. This has not been demonstrated at all.
Competing with established platforms that are more specialized to the task of focusing strictly on user experience is not an easy task. Steem/it needs to focus on and somehow exploit its unique advantages. In a big way.