The picture is funny at first glance but the reality is MS wants to reach far greater audience than your typical 3rd party publisher like EA, Ubi, Acti etc. ever will, ranging from smartphones, TVs, laptops, tablets, new and old consoles, and PC, literally everything that has a screen, at this pace it's just a matter of time when Tesla cars will offer GP as well, so from a gamer's perspective, the more studios they have the better.
But what Spencer meant is that studios working under an umbrella of a much larger publisher (once they become big/profitable enough a.k.a. "organic growth"
) means that the studio has lesser chance for failure/closure, and actually can continue to grow even further, because A) those big publishers have means to make a game more successful than a bunch of programmers who made the game ever will, and B) even if a game does't break the bank there are always other games/studios within that publisher who might make enough money to fund 10 new games, so at the end of the day the publisher is profitable anyway, whereas if you're all by your own if you fail once, it's over, and nothing will save you.
Take Minecraft as best example - do you think Notch would ever be able to make it as huge as is today by himself? Do you think he would've been able to make 2BLN$ on the game? Obviously not, the game has grew so much only because MS had the needed means, resources, and know-how. But like Spencer said, the studios have to go through those initial stages, prove their value, prove they can be successful and exist on teh market for more than just a year or two.