It's probably because Star Trek 2009 didn't do as well as expected, in foreign markets like the UK and Europe, where TNG had (still has) a huge following. One that even kept Nemesis reasonably afloat, in those markets, while it sank without trace in the US. Particularly Germany for some reason. Must've been all that expressionist architecture on Romulus and those Nosferatu bad guys.
Benedict Cumberbatch (even in the Hollywood "Hans Gruber" model of a Brit playing the Eurotrash villain) and a role for London, seems like a redressing of the balance - where there was (give or take 1 or 2 non-US actors in supporting roles) a largely American-centric feel throughout the Noughties with Enterprise and the last film.
Now I don't think that's a bad thing. Representation doesn't for one moment cross my mind while watching something. I grew up in the 80s and early 90s watching a mix of British and American shows, with rarely any kind of crossover. Whenever there was, usually each culture depicting a very stereotyped or tourist's view of the other. But somewhere along the line it became a bit more international, with Law and Order having a spin-off set in London and Torchwood upping sticks from Cardiff to the States. Star Trek TNG maybe started that trend by casting a wider net when it really didn't have to, not even coming back home to Earth all that often.
Of course, it's only the addition of a couple of scenes set in London and John Harrison probably isn't remotely British at all. He just has a naturally good speaking voice...