[W]hy is the riskier Mountaineers Route open, while the less risky Main Trail is shut down?
The answer is that the MR attracts far fewer people who are attempting something that is either beyond their skills and abilities or without someone like a guide who possesses the requisite skills and abilities. The majority of the rescues on Mt. Whitney are on the main trail or the chute, so at a time when social distancing is important and staffing levels are difficult to achieve or maintain, it actually makes sense from a risk management perspective. By waiting until the cables and chute are clear, they are probably eliminating a fairly high number of SAR calls.
Another factor is very likely the call volume. Remember,
all of these permits require a phone conversation now.
Yes, the call volume may be a factor. But that will only get worse as more campgrounds open, more places start loosening restrictions, and more people start travelling to the area.
The "waiting until the cables and chute are clear" rationale made a lot of sense previously but does not make sense now. Permits on June 20th are still being cancelled, even though the switchbacks were open by that time on every year during the past decade except 2011, 2017, and 2019 (all of which were heavy snow years, and this year's snowpack is considerably below average):
http://www.whitneyzone.com/wz/ubbthreads.php/topics/53085/when-will-mt-whitney-switchbacks-openhttps://weather.com/safety/news/2020-05-02-northern-california-drought-mayYou're right that the MR attracted far fewer unprepared people, but that's mainly because those people had the easier option of going on the main trail. If you take away that option, a significant fraction of them will try their luck on the MR.
Anyway, what happens if you ascend the MR but don't feel confident in going back the same way? Can you legally take the Main Trail down?
