When I lived in London I lived about 6-8 minutes from Edgware Road tube station, one of the stations impacted by today's terrorist attack. It wasn't the station I normally used for my commute, but it was probably the closest one to me. The neighborhood is as Garance describes it - heavily Middle Eastern, and the center of wealthy Middle Eastern immigrants in London, the ethnic community having been formed when people were getting rich off high 1970s oil prices and buying London property with their petrodollars. While it's a bit much to try to divine the precise intent of thus unknown terrorists, and I can't say if Garance's analysis is precisely correct, it is true that the choice of subway lines/targets is quite interesting - it did follow a path, roughly, from one center of Muslim London, the poor one, to the other center of Muslim London, the rich one.
...since it isn't clear, I'm not suggesting that the main point, the final sentence, provides evidence that Muslims were a primary target, or that this provides evidence that conventional wisdom about the perps is incorrect. It's just that, as Garance wrote, it's rather odd that they didn't target trains going around the circle line the other way - into Westminster - rather than those heading towards "little Lebanon," or some other line entirely. There are lots of potential explanations for this, including Garance's suggestion that it was to some degree designed to target Western Muslims. I don't have any opinion on that. I just think that this observation - "It certainly isn't the set of targets someone would choose if they were going out of their way to minimize the deaths of London's Muslim population" - is probably correct and somewhat interesting, though not necessarily ultimately significant.