A few points:
- The harder you lock it down, the harder they try to break in – Apple keeps things open and easy enough for Grandma to use, which also means really clever folks can figure out ways to hack the system.
- App makers who are concerned with the piracy numbers are app makers who can’t sell apps. Stop whining, start coding, until you have something people will gladly pay for.
- There really is no good alternative for developers – app sales across other devices is largely abysmal compared to iOS app sales… So, in a way, Apple doesn’t need to worry about losing too many Apple-friendly devs to greener pastures, especially not over app sales lost to jailbreakers.
- Apple can use the jailbreak community as a hostile skunkworks – sometimes, some really brilliant app ideas come out for jailbroken phones, and either prove that an Apple or carrier-based dev restriction is unnecessary, and can be removed in a future OS release (Google Voice comes to mind). This is especially great, because if Apple gets complete deniability with the courts and carriers, but get to see and “steal back” any good ideas which most users could benefit from.
- Jailbreakers are Apple customers – they don’t like some aspect of the official OS releases… Not modifiable enough being the main complaint. That said, they either refuse to migrate to Android (or soon, WebOS), or they’ve gone there, and run back screaming (I put it at about 50-50). Anyway, even when you agree to disagree, you still want to keep those customers, especially when you make much larger margins from device sales.