I thought The Sims started out as an architecture/interior design game and the social/life simulation stuff we all know it for came later.

The game’s emphasis on architecture and interior design dates back to its roots. Will Wright, inspired by the loss of his home in a firestorm, initially conceived The Sims as an architecture game, with the focus on characters added later.

I’ve seen it said in several places; this was the most credible-looking spot I could find on the first page of my search.