I have backpacked in California a few times, including a trip to Yosemite last year. All of these trips were planned months in advance, so the reservations were not a huge obstacle but they sure can take spontaneity out of the equation. Perhaps this is easier to accept with California weather where the biggest question may be a forest fire but in the Whites weather is likely a much bigger factor in go / no go decisions. I can see how someone could be pondering a presidential traverse because they had a permit for a given date even if the weather forecast looked questionable.
Having done Kephart and Leconte during Tropical Storm Dennis, I understand the idea of hiking in poor weather to fit into the schedule.
(I had a week in TN and if I had picked a different day, I would have missed Dollywood with my in-laws and kids who were five and two. We certainly weren't going to the Dollywood in a Tropical Storm. Dennis hit the coast as a Hurricane but the day I hiked, it was a TS. Eye passed to the west of GSMNP so I was in rain and wind bands on the eastern side.)
When you are local, you can cherry pick days. Local is somewhat of a relative term? (Factors include, price of gas, love of driving, how determined someone is, vacation time, etc) I know when in CT and more determined to hike, if the weather looked bad in NH but looked okay in the Catskills, I was driving NW not north. A front that impacts the Catskills around 2:00 may not get to NH or ME until evening when I would get off the trail.
I've parked at Cannon before and bicycled to the more popular trailheads in the Notch and then hiked back to the car.