Am I the only one who finds the forward/backward facing seats (contrasted to the side-facing bench seats) to be an anachronism dating back to railway days? Most of the major subway/MRT systems now seem to be opting for side-facing bench seats.
By having no more than three adjacent spaces, passengers are already choosing to stand when the seats are about 50 percent full. Seated passengers spread their bodies, legs and bags onto the adjoining space. Leg room is tight when facing a bench seat. Quite often one has to climb over a seated passenger to get to the window side of a forward/backward seat. Etc.
Of course, if one really wanted to maximize the capacity of cars, some of the new Singapore stock has the middle third of each car without any seating at all. It seems to work just fine.