Because there's no way to get apps any other way, there's no "open-source" app store for example. Therefore they hold more responsibility in what they let in.
Anecdotal evidence I’ve heard from developers is that there are a HUGE number of people who think that Apple makes all the software for the iPhone. It’s an Apple phone, you go to Apple’s App Store, so whatever you buy is Apple software.
It’s blatantly false, but it’s out there. Just like people thinking of Google as “the Internet“ because it’s the thing they see when they open their web browser. Someone recently said to me “did you know you they added image search to the Internet?“ because they noticed the tab in Google.
The other side of course would be the lawyers. If someone came to you and wanted to sue and you thought you had any chance in hell… would you sue the little one man operation that doesn’t have a lot of money? Or would you try and wrangle $1.07 trillion Apple into it? “They should have protected me.” Chances are Apple giving you $10,000 to go away would be far more than you could ever get out of the individual developer even with a full trial.
Apple could implement iOS-wide measures to prevent unnecessary network connections or data streams from sensors. They failed to do that. "Offending applications" exploit that incompetence Apple displays in the recent years.
