"Be anything, build anything!" So long as you can pay.
"DESTROY EEEEEEEVERYTHIIIIIIIIIING" Appealing to our poison-minded generation that likes to watch things blow up and people die, the kinda children that laugh their asses off at 9/11 footage.
"IT'S FREEEE" To those who don't have a problem with being vastly limited as opposed to "premium players."