So...

That means that developers who don't like iAd will go elsewhere meaning less apps for you - And that's better how?

Or to put it another way, how does limiting ad providers improve your customer experience in any way?

You're re-enforcing the "fanboi" image and saying you'll love whatever Jobs deigns to throw your way - Surely as a consumer you have an opinion on what you actually want other than "whatever I'm told to want"?