Life shouldn't be all about the money, agreed, but it is reasonable for someone to require enough salary to not run into the red every month paying for basic living expenses. Also, while money isn't a good motivator (see D. Pink), not enough money can be a terrific de-motivator.
Like anything, there's a reasonable-middle as to the salary requirements for an individual.
Given that Valve apparently makes >6 mill in revenue per employee yearly, I sincerely doubt that anyone they choose to hire is going into the red from normal living expenses.
Like anything, there's a reasonable-middle as to the salary requirements for an individual.