Dale, you crack me up comparing the Mt Whitney Main Trail to big wall climbing in Yosemite, glacier travel in Alaska, and river rafting the Grand Canyon. Most of the places you mention have nice toilet systems wherever there are large numbers of people hiking a particularly popular area like the Main Mt Whitney Trail. Your list of places where toilets are used include multiple locations in Yosemite High Sierra Camps and backcountry huts; Grand Canyon Angel Bright Trail and also Havasupai, Mt Rainier has solar or pit toilets at the remote campsites at various elevations in the snow (wag bags are used if necessary and are deposited in collection bins on the mountain - not packed out), Kanai Backcountry Lodge has toilets (award winning ecotourist destination, Gunnison Black Canyon campgrounds have toilets, backcountry in Zion NP there are pit toilets at Lava Point Primitive Campground. About the only place there aren't toilets is subzero Denali, but unfortunately biodegradable wag bags have not solved the problem. The majority of wag bags are thrown into a cravasse between Camp 14,200 and basecamp, 18 days worth per climber, 1,500 climbers per season. Here's a study explaining how wag bags are working out on Denali.

If you're interested in environmental protection, toilets provide the best environmental protection when there are large numbers of people involved and conditions permit. Rocky Mtn National Park is mentioned as an example of wag bags, but it's actually the perfect example of how toilets should be done on Mt. Whitney, as stated over and over again on this thread. If the RMNP engineers and rangers were in charge at Whitney, this is how it would be run. .

The American Alpine Club is quoted in support of wag bags, well they're quite supportive of backcountry toilets where they make sense, I've spoken to them about it personally. They are currently trying to raise $50,000 to install a backcountry toilet at Vantage Washington, so feel free to donate here if you're interested in helping them. They're at $42,000 and the other groups involved include the Washington Climbers Coalition and Frenchman Coulee Climbers Coalition.

Minor edits for grammar and links