The article didn't actually go into the detail of how much Valve pays.
"Valve pays people very well compared to industry norms. Our profitability per employee is higher than that of Google or Amazon or Microsoft, and we believe strongly that the right thing to do in that case is to put a maximum amount of money back into each employee’s pocket."
Considering that a ten year veteran at Google can make $200k/year, in salary + bonus + stocks, I'm curious if Valve compensation can reach the same level. The Glassdoor page doesn't suggest it can, but people may not be reporting their bonuses or profit sharing.