If you want to be cynical, you could say that Nokia also chose WP because of the all the cash Microsoft used to sweeten the deal, but we like Elop's quote for a couple reasons. Not only does it make for a good headline, but it seems to be a subtle jab at everyone who keeps saying (or starting rumors) that Nokia should adopt Android. WP makes for a "key point of differentiation" because everyone else makes Android devices.
Beyond that, Elop also said that Windows Phone "could be the biggest operating system in the world". Obviously, Elop had no specifics on how that could happen, but CEOs don't really need to worry themselves with the difference between "possible" and "likely". Many other blogs have led with this quote, but since it's nothing but marketing speak, so we prefer the other.
More in the full interview below.