It is a pretty clear cut we are talking about 16bit images not 8bit. When my workstation with 64gb ram is coughing an ipad will die under the load. Just don't call it PRO.
It's plainly obvious that not every professional user requires support for multi-gigabyte image files. I've never even used a workstation with 64GB of memory, despite being a professional Photoshop user for a long time.
Just a bit of a silly thing to complain about, really.