Microsoft puts a lot more effort in making Office fit in with the OS X system then Apple does with iTunes. It doesn't LOOK like a Windows app.
But unless you really need the strong (but actually, not perfect) MS Office compatibility, I don't really see the need for it. iWork is arguably better designed (for OS X) and far less expensive too, and has passable MS Office file format support. I feel like we are at the point that if Microsoft discontinued Office for Mac, it wouldn't matter much. Kind of like when Safari became popular and Microsoft stopped IE for Mac development.
The difference though, iTunes is a "must" for iDevices, which is pretty damn annoying in my opinion. Sure, you can avoid buying such devices. Android devices use standard USB protocols and can be used with a variety of software.