Most of us were SV in Dragon Soul, as far as I remember.
I played MM in Firelands though, and I liked the rhythmic nature of MM. It wasn't so much about focus management, but SF management and fitting aimed shots into a Chimaera Shot window (8s if you had the CD glyphed down to 9s).
The difference between then and now is that focus is a bigger limiter now than it was then. Because SS had a cast time, our focus costs were lower (iirc) and we rarely had the spikey focus flow I think MM has now. You could survive with just three SS in your ChS window (2 paired to maintain SF) and spend the rest on aimed shot with no difficulty. Now, in a Trueshot window, your AiS casting is limited by how fast you can generate focus. Now, the maintenance of vulnerable (and the stacking buff of PS) is a much bigger deal than maintaining SF, which was merely an increased focus gain buff.