iCloud’s Real Purpose is to Kill Windows

No. I use Pages (part of Apple's iWork) for almost everything. If I need Word comparability, I open LibreOffice.

Given how seamless the iWork experience is becoming between iDevices (which will be including Macs), how much cheaper iWork is, and how much better the iWork user experience is (they don't have 20 years of feature-cruft littering the interface), there is absolutely no reason for a home Mac user to use Office and few reasons (usually an iron-fisted corporate IT group) for a corporate Mac user to use it.

Doesn't my android phone already do this?

Facebook has recognised that it isn't the data per-se that is so valuable, but the connections and relationships that are between that data and others.. ie the way that your data is able to interact with other people's data. The way to lock people in is when a person's data alone is insufficient for them.

A music collection is just a set of licenses for songs. If people have only licensed the songs on a particular service or device they might find it painful to leave but if that pain is less than the cost of maintaining the service then they will leave. But a music community built around song collections would be impossible to leave, unless everyone did at once, or the person was willing to leave the community itself (much harder to replace than songs).