Why not pay back taxpayers first?

Why not pay back taxpayers first? « » Print The Daily Caller
The $15 billion aside, if GM is so profitable it can afford to give its new hires a raise and all its UAW workers plush health benefits and a big bonus, that’s great.
But why do I fear the economic assumptions underlying these numbers will prove to be unrealistic?
......Plus the whole new car market may be shrinking as the economy stalls.