How is a necessary evil, necessary?
I'm confused how are you guys happy that Apple can essentially assert executive control over your or my iPhone or iPod Touch? I don't like all this necessary evil stuff you are raising, beyond closing down potentially malicious applications all I see is another vector for attacks against this platform and for abuse on the side of Apple. Not to mention that calling home is widely seen by all as something that should be fully and completely disclosed to users, irregardless of the intentions on the part of Apple or for that matter any other manufacturer.
As I recall Adobe was recently slammed by the tech media for including code that called home, while it turned out to be rather innocuous, it still raised huge questions that ended in Adobe removing the code. Apple has a responsibility to its users to tell them when their software is calling home, rather than hiding it deep in application directories. But beyond this they should be offering options to turn it off, irregardless of the positive or negative effects of doing so.