Am I the only one that is able to go for more than 6 hours in a row without crapping my softshell pants? Does something about the hard-packed earth between the portal store and 10,000 feet magically squeeze the waste from ones bowels? It's magic! Some sort of Harry Potter wizardry?
I'd invite those day-hiking below the Whitney Zone to use the restroom at the trail head before they go. Might help.
Sorry to get back on topic, but the typical day hiker leaves around 3am and gets back in the afternoon. Do we need to get into statistics about what time of day most people take a crap? Surely nobody expects overnighters to hold it for two days. We talking 17,000 people a year - the capacity of an NBA arena.
Toilets have been a part of the Whitney trail experience since the 1960's. If you compare Long's Peak well-maintained system of solar toilets in Colorado to the wag bags littering the trail on Mt Whitney, I think it's clear toilets are the way to go.
I wish the Forest Service would have finished the environmental process and constructed new toilets as planned in the preferred alternative of the Environment Assessment. I'm hopeful they will work their way back to this solution over time.