Its not the fact of it accelerating slowly its the the fact that no matter how slightly you turn it immediately stops accelerating. You must be going PERFECTLY STRAIGHT to accelerate.
Newton says:
1. Every object in a state of uniform motion tends to remain in that state of motion unless an external force is applied to it.
2. The relationship between an object's mass m, its acceleration a, and the applied force F is F = ma.
Law #2 is the most powerful of Newton's three Laws, because it allows quantitative calculations of dynamics: how do velocities change when forces are applied.
In this law the direction of the force vector is the same as the direction of the acceleration vector. According to Newton, a force causes only a change in velocity (an acceleration); it does not maintain the velocity.
(you would get a different answer if you were conversing with Aristotle, however)