The best reason for pushing that I can think of is Newton's Third Law.
A "strike" involves moving one object at another quickly, at the point of impact, an equal amount of force is delivered to both objects and both are in danger of being damaged.
A "push" involves moving one object towards another, at the point of impact, an equal amount of force is delivered to both objects, and neither are in danger of being damaged, unless the one being pushed is caused to strike something else.
There is inherently less risk of damage to the giver in a successful push than a successful strike.