Android’s home screen is largely irrelevant to how Google makes money with Android. Google cares very much if you ship an Android phone with a different default search provider, with a non-Google default browser, without Google Play, or without Google Now. But replacing the home screen? Probably not a big deal.
I tend to disagree.
Facebook Home will reduce the exposure of the Android brand as a whole. Also, Google's own social platform, Google+ which is still pretty much strategic for the company will inevitably be hurt.
And last but not least, chances are good that FB Home users will tend to use Google's native apps and services less. Case in point: just a couple of months ago Facebook announced Graph Search and it is only a matter of time when it will appear in Facebook Home.
Personally I am not a big fan of Facebook. I don't currently use an Android phone (I was a happy HTC user for almost three years and I am still an active Android developer) but even if I did, Facebook Home would be virtually the last thing I would install on my phone.
My personal preferences aside, there are chances that Facebook Home will become a hit (maybe not right now, not this initial version). and if that happens, I doubt Google will be happy.
