In theory, a place could be so great to work at that people would pay to be there. That would be negative pot sweetening with money.
But the wage is determined by the least amount a suitable employee is willing to accept, which is affected by how interesting the work is and how "good" the environment is.
Then it's no longer a job, it's an expensive hobby / education / retirement activity.
Most people work jobs to support themselves (or others) financially, you can't do that on negative income.
And having more income than you need means you can retire sooner and do more of your desired hobby then, so it absolutely is a pot sweetener.
I've been in the $300s a couple of times, but my ability to get much useful done, joy of workmanship was completely washed out by the fairly nasty politics of the groups I was part of.
(I've never worked at Google, but after reading the internal message traffic surfaced in the Damore lawsuit, it's difficult to imagine enjoying it.)
I'm not 100% sure why Google keeps those people around, but they are fairly easy to avoid: just don't engage, no matter how insane their ramblings are on any given week.
FWIW, I loved my years at Google, and I think of going back from time to time. Is it an ideal workplace? No. But it's the best I have worked at by quite a margin. Why do I think that? Because Google is able to offer competitive pay and the projects that don't make your eyes glaze over right from the start, with the potential for truly breathtaking pay and world-leading projects with a little bit of effort and moving around internally, if you have the chops. It's not the best paying place anymore (that'd be FB), but not far behind, and on the balance it more than compensates for that by offering more meaningful work and beyond state of the art dev infra.
Disclosure: I no longer work at Google, and hold no positions in its stock. They treated me well when I was there, so I wish them well.