I think the people who complain about this are genuine speedreaders.
The endless are effectively ghosts, they are algorithms and data based on living people, and are not alive, never have been, never will be. Not even all of the "endless" are properly in a state of revival at any given moment, and Living Memory has so many parts of it that are rundown and not even functional anymore.
The whole point of Sphene's character is she can't let go. Not of the past, not of the people who are long past. Death is the natural order of things, so keeping people alive has an obvious drain on those still living.
I have seen people try to say like "Oh, the creatures in Ultima Thule are actual living beings" and you know that is 100% a special case due to Meteion's enormous amounts of dynamis at play.
There is no ethics problem with ending the endless. These people are already dead. We're just allowing them to pass on. Cahciua spends the entire Living Memory segment of the MSQ HAMMERING this fact into your head.