I happen to agree with the approach. MS and Activision are are companies incorporated in the USA and follow USA law. I wouldn't have a jurisdiction outside of where I am incorporated dictate what I can or cannot do as long as it does not brake any laws. So if the UK, Europe, China, Russia, Canada, Australia does not like what I am doing I can go sell my stuff somewhere else.
Like I said before the UK revenue for MS is about what Activision contribute in profits alone. So financially having Activision and dropping the UK is a much better deal for MS.