> But guides and hotel staff ... tell them they are at risk of dying, that only immediate evacuation will save them.

I got Acute Mountain Sickness at just 11k feet. Headache, nausea, dizziness, fatigue. I passed out until hitting the ground woke me up. I was very disoriented and vulnerable. If someone had told me that I had to get to a hospital or I'd die they could have led me like a tame goat. And they could be right. If you have high-altitude cerebral or pulmonary edema it is life threatening.

A guide getting a kickback can make it a lot more likely just by cutting short the boring acclimatization time.