If Krakauer is being honest, pretty much everyone at Base Camp could be considered "clinically delusional" (7.6). But that's par for the course as Everest goes.
For example, a Canadian named Earl Denham once snuck his way into Tibet to climb Everest back in 1947. This utterly inexperienced climber even convinced Tenzig Norgay (one of the first two men on Everest) to tag along, though his attempt ultimately failed.
There's also Maurice Wilson, who hatched the insane plan of crashing a plane into the side of Everest to get a head start. When that plan didn't get off the ground (literally), he attempted the climb via the traditional route. His body was found a year later.
Though there are plenty of nut jobs here with Krakauer today, there are also many experienced climbers. There's Klev Schoening, former member of the U.S. Olympic ski team, and his uncle Peter Schoening, a "living Himalayan legend" (7.18). There's also Charlotte Fox, who has already reached the peak of two mountains above 8,000 meters. All of these folk are on Fischer's team.
Oddly, the "noncommercial" (7.23) expeditions are shadier than the commercial ones. The Taiwanese expedition, in particular, seems super inexperienced.
To tell the truth, though, the worst of the bunch has to be the South African team, sponsored by the Sunday Times newspaper from Johannesburg. The team is led by Ian Woodall, a dude who claims to have fought as a commando for the South African military.
Woodall started by hiring Andy de Klerk, Andy Hackland, and Edmund February, three extremely talented South African climbers. Edmund February also happens to be black, which is considered an admirably progressive move in post-Apartheid South Africa.
Woodall also wanted to bring a female climber, but was unable to pick between two candidates: Cathy O'Dowd, a white woman, and Deshun Deysel, a black woman. He decided to bring both, claiming that he'll decide who will join him on the climb after seeing them in action.
Given this, Krakauer is shocked to see February, Hackland, and de Klerk leaving Base Camp. As it turns out, the trio "resigned […] before even getting to the base of the mountain" (7.34).
It turns out that Woodall completely lied about his military service, among many other things. Namely, he had only gotten a climbing permit for Cathy O'Dowd, not Deshun Deysel, which has some gross racial connotations. Plus, dude isn't even South African—he's British.
Upon learning this, the Sunday Times renounces their support for the expedition. Woodall already has their money, though, so it doesn't end up making much of a difference.