That was a very interesting article. While I have no idea as to why airlines tend to use a 3x3x3 configuration on 777s, that won't stop me from speculating. Obviously, most travelers prefer either a window seat or an aisle seat. Either the 3x3x3 configuration or the 2x5x2 configuration results in the same number of aisle and window seats. However, in the 2x5x2 configuration, the person at the window seat has only one person to bother if needing to go use the restroom, whereas in the 3x3x3 there could be two people to bother. Having 2x5x2 seating means that the people in the center seats in the plane have two people to bother rather than just one, but I presume that those seats are the last to fill. Thus, it appears to me that the airlines are looking at the inconvenience posed by people going to the restroom as being more important than the potential for having people seated adjacent to each other.