I first started playing due to curiosity. I quickly became addicted. I play for several reasons: pure entertainment, designing houses, its fun to observe them too. I feel like a mother taking care of her kids. I make sure they do the right thing and have everything they need. I even spoil them. I never had kids so I guess that is why. A friend of mine has a God complex. He likes have power and control over them. I prefer to allow them to do as they please, but if they are kids, they must do their homework and help with chores.
It is kind of like being able to manipulate characters in a movie. well, manipulate is too strong a word. I mean more like contributing to a movie.
Plus, they are just so plumming cute ! :) It all boils down to fun.