Why did CHRISTOPHER HITCHENS and CRAIG FERGUSON 'become' AMERICAN CITIZENS???

Among many other 'new citizens' CHRISTOPHER HITCHENS and CRAIG FERGUSON became 'AMERICAN CITIZENS' recently. WHY??? Why have an ENGLISHMAN and a SCOTT - blessed with the same language and a culture of freedom established longer than our own AMERICAN traditions decided to 'become' citizens of the UNITED STATES of AMERICA??? Could it be for certain [if there are?] 'tax benefits??? Could it be because both [FERGUSON the comic/actor and HITCHENS the writer/pundit] have a greater 'marketability' of their talents in this country??? WHY??? With all or many of us[read DEMBHOLES complaining/carping/kvetching about how AMERICA is despised over the entire world and our national prestiege is shot-zilch and we are a pariah nation in the world's conclave] saying our nation is in decline - WHY ARE THESE TWO (AMONG MANY OTHERS) SO DESIROUS OF UNITED STATES CITIZENSHIP??? Why indeed??? ["A perfect government is never formed by imperfect people" - ALEXANDER HAMILTON]