It could be called this aptitude test if all posters got reset to lower ranks and had to earn merit to advance. Since higher ranks got a lot of merit for nothing, same as old, abandoned accounts, that were later traded and used as merit donors, the system is not perfect. At least it does not act as an equal test for all members.
Since the rank requires activity points along with Merits (now), and activity points are earned by posting, then resetting every single member of the forum to lower ranks would have meant to delete all the posts they have made until now which is the only way to reset their activity points, and doing that would have cleaned the complete forum and there would have been no posts in any section of the forum after the new system which would make no sense at all.
Besides, not all the higher rank members are undeserving, and they all earned their positions by being active on the forum for so many years since it only required activity to rank up before the Merit system. But still, what I said earlier is the reason why theymos could not reset all the ranks and demote every single user of the forum. It would then be a reset for the forum itself which wouldn't be a good thing for any of us.