[CoolGuySteve]

It's the app developer's responsibility to update and QA their program.

If Apple allowed dynamically loaded libraries across the OS, then subtle issues in an App update could cause that one update to break seemingly unrelated apps. Windows developers call this DLL hell, and even with manifests and SxS, Microsoft still doesn't have an attractive solution to the problem.

Meanwhile, from a security standpoint, the sandbox should prevent apps from interfering with the files of each other and the OS.

And from a performance perspective, the few kilobytes (even entire megabytes!) of duplicated code segments is inconsequential on a phone with 1GB of RAM and very few context switches across apps.

[skue]

No, you are conflating two separate concepts. Just because a framework is dynamic doesn't mean it has to be shared. MacOS X provides all the benefits of dynamic frameworks that Landon outlines, but third party frameworks are almost always bundled within each app (and on iOS they would certainly be required to be).

[itripn]

I am not actually conflating them at all. However, Frameworks as implemented on iOS are at present dynamically loaded. As I said, there are technical ways to address that particular issue, some of which bring iOS Frameworks more in parity with OS X.