well it's also the same way with the sith. like, there's only 2 "sith" but obviously that's nonsense because there's all kinds of bad guys with lightsabers. it's very similar with the jedi, they hoarded all the knowledge so no one could learn the force without their express, written consent in triplicate. you basically get the impression that the jedi are SO pompous that they don't even consider ahsoka a threat. like, there's NO way she COULD ever teach anyone anything. ahsoka on the other hand very much wrestles with the concept of SHOULD she teach anyone anything, but she ABSOLUTELY COULD.
ultimately they are both wrong for the same reasons. the jedi absolutely lost sight of their purpose and needed to be culled. whether or not that's what lucas meant when he wrote the line of anakin bringing balance to the force, that's exactly what happened. and obviously you can interpret it multiple ways in that anakin brought balance by fathering luke, or that he brought balance when he turned back to the light or whatever but it REALLY happened when vader went after the younglings, hard reseting the jedi order.
the jedi order functionally became the vogons from hitchhiker's guide. they take FOREVER to actually do anything, and then when they finally do something, they are so committed that they can't be bothered to stop and think about whether or not the situation has changed.