It really isn’t. FB/Goog compensation is still the benchmark as far as industry comp goes, so a private co really needs to be convincingly successful to attract smart, high paid engineers at top tech companies. If they can’t then it’s a completely valid signal that something is up - either comp is well below market, growth story is fishy, management is weak, or something else.
His assumption is actually that smart engineers would chase good tech, high stock price increase potential. They already have good compensation being Facebook/Google engineers.
Work environment makes a huge difference. My current job is pretty harmonious among the coworkers, the bosses and team-leaders are all engineers themselves or at least tech-literate. They are also very preoccupied with the welfare of employees and even kept a completely unproductive (bad fit) employee on for half a year to help him score a new job first.
The customers are almost always happy with what we produce, and while it is certainly not fast growing, the company is steadily progressing in a good direction.