I ask this question in earnest - what's in this for Apple, why is Apple doing this?

I haven't seen anyone who likes this direction taken by Apple. Why would they do something that has the potential to detract from their product demand. Apple always said "We're different - we sell you our products, we don't sell your data." Now, they're giving away the data and for what? Child safety - I don't buy it.

I remember when Apple refused to help law enforcement unlock the iPhone of a mass shooter is California. Why the change of tact now?