But that's when the Skyliner is moving. There have been numerous honest evaluations stating that the gondolas get very hot when stopped and that when moving the amount of gondola ventilation (and hence comfort) largely depends upon which why the wind is blowing. If the gondolas are traveling in a following wind, they get hot because the ventilation is reduced.
It's clear that on a hot and humid day, getting stuck on a gondola for more than a few minutes will be very uncomfortable. For a longer period some guests will suffer heat related health problems dependent upon their age and general health. And those health problems could be very serious if the victims are left stranded in the gondolas for several hours.
And what I have stated is not a skeptical analysis, but rather just the plain facts of the matter.