All good points that are certainly worth consideration by the WPA Rules Committee.
Another problem is that it is possible to miscue and have larger-than-normal CB deflection with only the tip striking and quickly sliding off the CB, with no secondary contact with the tip, ferrule, or shaft.
The general philosophy of the rules is that a foul (double hit, contact with shaft, etc.) should not be called unless there is clear visual evidence that a foul has occurred, and any benefit of doubt must always go to the shooter (no foul).
To properly judge if a miscue is actually a foul or not, super-high-speed video equipment would be required filming every shot. That is not practical.
Now, as you suggest, the decision could be made to make all miscues fouls; but again, I think this would be a really hard sell, and "the devil is in the details" of how such a rule would be worded so it could be applied consistently without too much judgement required. It might be difficult to "pick a number" for an acceptable amount of CB deflection for a non-miscue shot. And again, "partial miscues" and different types of miscues can create a wide range of CB deflections from the ideal path.
It might be easy to say: "I know a miscue when I see one," but the rules must be very precise and easy to apply consistently.