While a go-around is a routine procedure, it is also a very demanding one. As has been noted, the first responsibility of the pilot (and as was drilled into to me time and time again in my own private pilot training, "First, fly the plane") is to safely execute the go-around. In busy terminal airspace that also means watching diligently for other aircraft, stabilizing the aircraft in a new flight regime, talking as required to ATC, etc.

I agree that it would have been nice for the pilot to have made an explanation once on the ground. But I also can imagine that many would be the first to excoriate the pilot for a mid-air that resulted from the inattention to the task at hand because he/she was making a cabin announcement.