I have intentionally attempted to shift my mobile habits to take advantage of new, well-done applications. I tried to replace iOS's safari with Google's Chrome application. And now I am trying to replace the core iOS mail app with Mailbox. In trying to do so, three obvious points come along: 1. There is much innovation to be done around core experiences. Ones that come to mind: MessageMe for messaging, Mailbox for mail, Chrome for browser, Tempo for calendar, etc.
2. It is really hard to break personal habits. Regardless of whether or not I prefer Chrome to Safari - I am rooted historically and routinely in Safari. I like the Chrome browser a lot, but find the littlest things annoying - not because they are poorly designed or created, but because they are different than where I habitually expect them to be.
This of course is in conflict with point #1 above: innovation challenges habit. And habits are hard to break.
3. It is far harder (nearly impossible?) to break device habits. What I mean by this: if you really prefer Mailbox to iOS mail - you have to go out of your way to use it as a default... and it is even more challenging in the Chrome example. Being built into the core OS is such a huge hurdle to overcome - and while it may not stifle innovation, it stifles adoption.
Of course it is different from OS to OS (Android's flexibility is why apps like SwiftKey are so great and so popular) - and even more complicated with various device / hardware layers.