Even if Google were paying support engineers $100/hr, in what universe is the average developer going to need 50 hours of support per year? In reality, it's at most averaging to 2 hours, and typically only in situations where Google messed up and should really be fixing it for free anyway, because it was their mistake. So, at most, it would be a labor cost of $300/yr including benefits and taxes, and more realistically that number is much closer to $100/yr.
And that's pretending they don't already make obscenely high profits per developer, and can absolutely afford to provide the necessary support for these situations, which again, are largely their mistakes to begin with.