Nokia was on already on a downward spiral when Elop joined. Unfortunately he accelerated - rather than halted - the decline and did so in the most humiliating way possible for the company (allying with the old foe).
He's lucky that the Ratner Effect had already been named after someone else.
The Sonos CONNECT:AMP acts as an amp (unsurprisingly). If I were to use Apple TV/Airport Express, I'd need to buy a standard stereo amp and leave it powered on permanently. It would be a two box solution, rather than a one box solution, and I'd lose synchronised playback functionality. It would be a worse solution for more money.