The acquisition isn't the result of a Mayer-esque spaghetti-against-the wall buying spree. Withings doesn't represent an existential threat to Nokia, so it's not something they'd like to watch whither on the vine. And it's not a robo-dog pet project of the week. Acquisitions are justifiably met with trepidation in general, but this doesn't seem bad.
I guess I just don't really understand the letter you'd have him write instead.