You are right of course that taking out new directions calls for leaving old paths, replacing old tools with new ones. And if Apple wants to improve online document creation and sharing, that's all very fine.
It's a shame then that the collaborative possibilities of iWork, currenty in open beta, are so limited (Want to collaborate on a Numbers document with an iPad user, for instance? Not possible.). And I'm not sure how killing very basic features - like margin settings - helps us reach new ground. I for one almost never print out spreadsheets on paper. But I do create and share a lot of pdf:s, and I want them to look good. I want control, not "good enough" (heck, Microsoft used to be about "good enough").
Whenever Apple dumb down an app for the sake of parity with iOS versions, they are basically hammering the message that iPads and iPhones are less powerful than a computer. Developing easy and elegant ways to perform certain tasks with a touch interface and limited screen estate is hard. Most of the time Apple not only succeeds, they shine. But just because they sometimes can't nail it, should that mean that they must kill the same feature in the desktop version?
Like you say, a lot of things we use computers for are rather mundane and far from cutting edge, and it's pretty clear what Apple wants to be perceived as. But just because something isn't cool doesn't mean it isn't useful, or even requisite.