The Rotation is not what makes BM really easy. It's the freedom you have. Because it is ranged with no "cast time abilities" it feels like you have unlimited mobility. Plus the short CD's make you able to use them on demand with no real worry of having them ready later. The spec just allows you to play with no real need to think of your placement or plan ahead. You can just take the fights as they come along. It's a carefree playstyle which is really nice for mythic raiding progression.