No, unions exist to allow workers to excersize their collective power to bargain for better wages, treatment, etc.
Unions don't set non-union wages and make up a minority of
wage earners in America. So, since unions were not part of the discussion until now, I must assume you have their perspective out of whack and at least a mild bias against them coming into the argument.
As for what is reasonable or unreasonable, that is determined by the market. If GM could not afford to pay the wages, they would not be paid - union or no union. Simple as that. So, your beef isn't with unions, it is with supply and demand. And no real surprise there. The entire effort consisting of the use of foreign labor, illegal immigrant labor, And imported Visa based fraud labor has been one of trying to undermine supply and demand by undermining the local market with those sources. That seems to be why these big three attacks + free trade seem so loved by the ethically challenged in the GOP and Dim party and why America is screaming about it to deaf politicians. Ya'll don't like supply and demand and to cover for your own failings, you attack us and say we don't like Capitalism. You lie about us to hide your own shortcomings. Unfortunately for you, everyone sees through it.
So, again, your opinion on what "sounds reasonable" by way of wages, is useless. The market decides it, not you. You aren't happy with the market and supply and demand and have opted toward breaking both using unpatriotic and subversive methods. And that may lead to war.