I play it for the same reason I played with action figures in a sandbox when I was a kid. That also includes having special sets(like the star wars garbage compacter set). These would be considered "theme park" ideas that I used in that same Sandbox, or next to it. I liked both. MMORPG's allow this same creativity but with virtual reality instead of plastic figures and real sand. I can also now appreciate story telling a lot more this way as well, as long as my character is part of that story. This is my reason for playing MMORPGs.