Completely agree, Bowlinmoe! You are not the only one who noticed this. The first time on the Joy was so disappointing because of it. The biggest issue we had was whenever we went to the shore excursion desk or Guest Services, we couldn't hear the people at the desk. It was so loud. They got so frustrated, as did we. And there were so many people standing around, it was hard to get to Guest Services. Same thing on the Encore (which we really liked except for the Atrium). I think holding some of the less busy activities there works fine, but with the more popular ones it's such a zoo. We will just avoid the atrium altogether if we ever sail on that class again or stick to the Jewel class.
It sounds like the Prima/Viva may have eliminated the atrium annoyance with a better design. We have a trip booked on it, so we will see. Sail on! 😄