London is not "an extra two hours in a plane", it's more like an extra 7 when you consider all factors. But regardless, you're missing the point.
It is a matter of competitive advantage. In basketball and hockey, every team is travelling and playing games every couple of days, so they're all in the same boat.
But if 1 team was stationed in London, with all the rest in the U.S., then that team in London would be at an extreme competitive disadvantage. Travelling to every single road game would be anywhere from a 10 to 15 hour long ordeal, not to mention a 5 to 8 hour time difference.
It would be a physically exhausting and grueling schedule for the players. The coaches would have significantly less time to prepare for every game. Free agents would avoid London like the plague. It would be a joke.
10 to 15 hours ordeal? wow I didn't realize they were traveling to Central Asia. Plus it is not like they have a game the next day, I think most teams get Monday off after a game? right? Did you get a chance to see the planes the Pats flew over in? Not quite the same as flying coach.