Yes, California salaries are more expensive than Europe. Yes Europe has more laws. There are trade offs.
If your business is boom/bust (lots of hire/fire) then Europe is expensive due to worker protections and smaller talent pool.
If your business has anything data based, or other high-regulation topics, Europe is expensive due to their regulations.
If your business just needs warm bodies to iterate on some codebase, Silicon Valley is expensive.
Or, in the case of Evernote, if you’re a Silicon Valley based company that doesn’t push the cutting edge and you lay off most employees AND you’re purchased by a European company that has European employees, maybe stay in Europe.