True that regarding water. Most probably do not realize that water is pumped up to the South Rim.
Also, as you know better than anyone else, backing tracking from Phantom Ranch / Bright Angel to the Black Bridge is no trivial matter. Worse, will be the folks who foolishly decide against taking the River Trail to Bright Angel and then ascend South Kaibab unprepared. People will reach the Tip-Off and realize that the only potable water lies another ~4.5 miles up to the rim or across the Tonto to Indian Gardens.
I suppose the new Tip-Off shelter (which I have yet to see personally) may alleviate matters some.
www.nps.gov