Don't just think of the US job market for Software Engineers as the Bay Area, not that SV or the Bay Area is bad. It is just that there is a huge market opportunity outside of Cali and frankly I think the cost of living and salaries are way better in other areas. I lived/worked in Austin for awhile and that is hard to beat. But so is Florida (where I am now), and a ton of other places. NYC and Boston as examples don't necessarily beat Cali by much in the cost of living but they sure make up for it in diversity.
No matter what, no, the Bay Area is not the only place to work as a software engineer. Nor in my opinion is it even the best place to be. I will admit that it is the most popular and most publicized and so has some credibility and perks to match, but really, that is not what makes the work. I know nothing of the Switzerland market so I can't comment on that. But I can say the East coast of the US is doing well and getting better all the time, and the amount of creativity is awesome. Not to mention you have Austin, Seattle, NYC, Boston and many other places to choose from.
Good luck and don't let the SV hype get in your head, there is more to the world of Software Engineering then just Silicon Valley.