I wouldn't say that Jobs was saying to treat customers as idiots.
Listen, people can't anticipate what you might come up with that is new and better than what they've seen before. It's the job of the artist to surprise and delight.
As for writing for an audience.... it's not about catering or pandering. It's about communicating. If you're going to surprise and delight (rather than confuse and annoy) it's good to know what the audience already knows and expects.
The trick is this: if you have to warp your work to suit an audience, you're going for the wrong audience. So maybe when someone asks you "what audience are you going for?" that isn't a critique of how you should change your work, it's just a relevant question as to what are you going to do with the work when you're done.