My memory is a little cloudy, but before the App Store, was there a vibrant developer community for the mobile/PDA app market? There should be one correct, since there's already a lot of mobile devices capable of installing apps before 2008?That cuts both ways. Where would Apple be without the vibrant app developer community?
Besides, people forget that the original iPhone didn't have an app store when it came out. Jobs envisioned that everyone would use web applications at the time, which wouldn't allow Apple to play these games.
I remember carrying a Palm IIIc back in the days, but I don't seem to find a lot of apps I can install for it. Ended up using it as an organiser and an offline news reader while travelling on the train to work. Those were the days ... but I digress.