It’s hard to imagine why Jobs would have such a grudge against Flash.  Why would he lock out the most popular piece of software in the world from the iPhone?  (Flash is more popular than any particular browser or OS)  With the early success of the iPhone 2.0 app-store, it became clear:

Had iPhone supported Flash, most of the killer apps would have been developed in Flash, and then easily ported over to the next hit phone

Many people focus on the first 2 benefits of first mover advantage: that you can have a head start in market share, and the extra time-value of money is nice too.  But what’s really the sweet spot is to develop a proprietary platform that wil be incompatible with anyone who tries to play catch-up further down the road.