I think Apple has learned from their mistakes, such as when they introduced the Newton and it was a failure. The technology was awesome, but the environment wasn't right. Also, with the iPod, they were by no means the first to market, but they had better technology and people were already comfortable with digital music. The introduction of the iPod confirms the fact that they introduce products at the right time.
Lastly, the iPhone was successful because of the data transfer speeds available on wireless networks at the time of introduction. Had they introduced this product before, it would just have been another competitor to Nokia, and not the incredible force that they became. Here is a historical map of product introductions from Apple.
As you can see, Apple introduced very innovative products that were not very successful before Steve Jobs got fired. I believe this allowed Steve to reflect on his failures and when he came back he introduced very successful products at a time when they were needed and would be a success. Farewell Steve.