That's a phone, and they've taken a different approach with security for those. The product they're offering is one where you're more restricted in what you can

That's a phone, and they've taken a different approach with security for those. The product they're offering is one where you're more restricted in what you can do, but you're given more security as a trade-off. For their iOS products, more locked down equals more safe. They're treating them more as appliances than as general purpose computers. For consumers this has some appeal: The risk of malware and trojan/virus like applications is effectively zero on iOS. If there was a way to offer security without locking things down they'd probably do it, but I think that's a logical impossibility. If you don't like that model you have a ridiculous number of alternatives, more so than in the PC space. So this is less a case of Apple using DRM when it suits them and more a case of Apple using DRM when it suits the consumer. Running only trusted, signed applications is a limitation, but it's one that is not without benefits.