It's what I always find with open world games for example. No matter what kind of character I build or how I behave I'm only ever going to get predetermined dialogue which I could have looked up and saved myself the time.
Yes in the sense of the Sims it's probably overkill (they sold millions of copies even without a script) but it's only being used as a playground to test the ideas and see what's possible, there's no suggestion that this is particularly what the Sims itself should be.