It's easy to magnetize, easy to erase. But there are other problems that low coercivity brings about. This limits the amount of signal we can store. If you try to put the data pulses too close together the second pulse while being recorded can help erase the first pulse because while the magnetic field is concentrated at the gap it exists outside this are. A north pole of a magnet will attract a south pole of another.
Opposites attract, and likes repel.
One north pole will try to repel another north pole. In the original disk formats where the data stream was kept constant - the bits on the inner tracks were closer together than the outer tracks. Bit-shifting would occur on the inner tracks, but the data patterns which cause this were predictable so that when you reached a certain diameter of the disk you would change the writing pattern to compensate. Thankfully we don't have to worry about that in today's world. This gives rise to a phenomenon known as 'bit-shifting'.