Finance can be (much) better, but feels like far fewer jobs, especially outside Frankfurt. I'm not sure finding a high paying finance jobs is easier than finding a software job at the German office of an American firm (which pay similarly well).
> I suppose factory workers cannot be let go as easily.
It's important to look at comparable companies. If you're a SE at a company with many factory workers, firing the SE is usually equally as difficult as firing the factory worker. They usually have the same protections and are in the same union. Software shops just tend to be smaller and those have lower job security.
There's a reason why some European countries loosed up to 30% of their population to America-bound emigration.
Consider also that if you're a German, your own country hates you and your very existence. The US doesn't have anything against Germans.