What Steem has going for it is the fast block processing time and no direct fees.

This. The "average" gamer does not want to wait for the item(s) he earned by playing, or anything bought in a game (i.e. microtransactions). Nor does he want to pay activation fees etc for those items. $.99 for an item? Sure. Buy. Go to inventory. There is my new fancy gun/card/hat/whatever. Equip. Click play.

Waiting for items to appear in the inventory is not in a gamer's nature (in general).