Having said that, I think the intention was to describe Palantir in relative terms compared to other companies in SV. With that in mind, then yes, Palantir is one of the worst places to work at among companies of the same type: well-funded startups with a rather convenient revenue stream.
There are people who legitimately enjoy super high intensity environments. There are people who legitimately loathe low intensity environments. If you're not one of those people, you're not going to have a good time at Palantir — this is not a secret. This is stated over and over by everyone. Shyam (head of BD) has a public blog post shaming the very notion of work-life balance. No one is tricking anyone, except candidates fooling themselves into believing everyone is lying and it's actually a chill place.
Ultimately, the sweatshop analogy is pathetic on this basis alone: you have a choice to work there or not. Working conditions aren't really the problem with abusive employment. There are people who take on far more life-threatening and limb-damaging jobs than a sweatshop.
The key distinction from those people and those who are abused is that they are free to leave and thus free to demand proper compensation.
No Silicon Valley company is a sweatshop. What a delusionally entitled way to see the world.