The vertical angle shot is not easy to catch, and traveling greatly improved my odds of burning successfully. It is from the point of view of the defending team taking the expected option. The defending team can take a point for the out throw instead of charging an infraction. The team calling the infraction will have too big an advantage. Angle is an accident, and should not be punished too severely.
Angle is a subjective call.
No one can tell the difference between 29 and 30 degrees. There will be more angle calls. They are awarded a point in a situation where they should get one. 2. Steep shots have their advantages. Intent is moot in the making of a good rule.