If some revolutionaries came up to me and said, "We're making a new, very big state that's very existence is gonna change the balance of power on the continent*, do you want to lead it," I'd say yes in a heart beat. But Frederick William IV rejected the offer. Why?

*The creation of the German Empire in 1871 upset the balance of power of the Concert of Europe, as one would expect from a couple dozen countries coming together to make one big one, so I foresee that this would upset it even more, seeing as it was larger. Then again, this one would be created after a revolution, not after defeating one of the great powers of Europe hot off the heels of a victory against another four years prior, so maybe it'd be different.