The original premise of an iPhone was that closed experience. It was an improvement over the mobile market that existed back then. I remember because I had my fair share of Philips, Alcatel, Nokia, and ipaqs. What I’m afraid of is that some actions and reactions of a—let’s be honest—insignificant number of power users who want to root their phone is going to break the experience for the majority of the regular users. Progress is welcomed but let’s not forget: the road to hell is paved with good intentions.
The original iPhone had no App Store and thus no way to get third-party native apps at all. I don't know that the original premise is at all relevant now.