> Several consultancies will happily open a "paper company" for you in Ireland or wherever you choose. No problem whatsoever
Not every company is willing to spend this much on marketing.
> "Talent goes to Mountain View" 
Read up on the story of Lars Bak.
> There are a lot of talent outside the US (V8 came from Germany, also Zurich, London and Dublin offices have technical openings, Australia, not to forget Belo Horizonte in Brazil) and inside the US (NY comes to mind)
Openings that have been "open" for many years. If you get through you will be moved to Mountain View, CA.
You are overestimating the size of Google's (internal) marketing, and don't know how marketing is structured for companies like Google, also you seem to not understand how multinational tax structures work, so I won't explain any further.
"If you get through you will be moved to Mountain View, CA"
That's not what happened to several people that work or have worked at Google that I have personal knowledge of.
Some will go to MV of course, depending on area of work.
Lars Bak? "In 2004, Bak joined Google to work on the Chrome browser. He did not return to the United States"