In my imagination I speculate that the initial component placement task would be easier if you could disable the ratsnest display of GND connections, just to reduce the amount of visual clutter on the screen. Same could be said for other nets with many nodes, such as power rails. If it’s a multilayer board with dedicated layers for ground and/or power connections, the ratsnest lines that will be connected on a dedicated layer are probably a hindrance to efficient component placement than a help.
Even on a two-layer board my personal working style generally starts out with at least a mental image of how I’ll distribute power and ground. As I initially place components I give most of my attention to signal routing, and mentally almost ignore the ratsnest connections to power and ground.
But I don’t recall ever having a tool that could omit some nets from the ratsnest, so I don’t know whether or not my fantasies would live up to reality. I definitely would NOT want the undisplayed nets to be ignored by DRC, unless it was a general DRC option to “Check all track widths and clearances but ignore any unconnected nets.”.
Dale
p.s. - I also make explicit trace connections to all nodes in a net before I fill copper zones. I think that was required by some tools I used in prior incarnations, and it just seems like the safest thing to do.