I suppose God could have created us all as drones, but He created humans to have a will of their own. With a will of our own, some of us will make good decisions, some not so good. We all have the capacity to choose bad over good, good over bad. We only tend to question God on this front when we see people doing bad things, but when people are generous, loving, kind, etc...we don't question the why of our own will.
Because human nature.
Because human nature.