Maybe there is already, but a cap on how much the cost increases for redistributing points would make the character building much more user friendly. After having leveled 10 or so to level 30 the idea of trying new things is starting to wear thin. The cost per point balloons to unattainable numbers and coupled with the fact that you cannot back points out of a mastery bar it just becomes a hassle if you later decide you are not liking your character. Having already spent a few dozen hours leveling up characters in the early game the last thing I want to do is make that long slow run on the warden again.
Ideally one would need to level 6 characters to have the flexibility to try any builds. Points invested in the primary mastery bar, the first one chosen, can be fixed, but the skill points and those in the secondary mastery bar should be flexible. I really do not wish to start again to try a new idea after a certain point.
From a gameplay standpoint there is no reason for this not to be possible. If the goal is to have fun, the restrictions of endlessly inflating point cost and locked in secondary masteries seems like a mechanic perfectly designed to inhibit said goal.