Those ranks are just a perk for members. Yes, you "move up" after reaching certain post numbers, but it's not a measurement of your contribution quality and we certainly don't see it that way.
Says who? Where does it say that? Your implications are just that, implications.
Many members do it the same way. They just have been here longer and thus their post count may be higher. Even if you don't participate in every discussion your posts do add up in time...