If you have bags of cash and are ok with the idea that your platform's defining franchises and devs will eventually go elsewhere if you ever stop spending what they've come to expect on them, or if your platform suddenly becomes the less popular one, sure. It's like the rich kid buying his friends.
If they're prepared to keep up the spending for Xbox One over the next 7 to 10 years more power to them, I suppose - they'll be building a library up either way. But it's worth noting that the only dev they have left that has created games for them with a >90 metacritic is Turn 10 - a first party studio that they've grown from the ground up and nurtured over a long period of time, like any good first party should. So maybe they should think more carefully about where they want to invest their money, and whether the long term gain of a proper first party studio trumps the short term gain of third party moneytrucks.
