As a rule, I dislike working with humans. Their sense of morality only vaguely resemble ours, and the difference in power is such that we spend more time protecting them than actually doing our duty on the rare time we do fight alongside.

[Well, except for Ichigo and co, but none of them are what you'd call run-of-the-mill human.]

However, it is my duty as a shinigami to portect human souls, wherever I may be. And being human doesn't per se disqualify anyone from being involved in this venture. My own shortcomings in this area mine to overcome.

I have noticed, though, that there appear to be relatively few humans around.