What people are failing to realize is that references are not necessarily "former employers" but often third party professionals. My references include collegues I may have once worked with but they have moved on, former bosses, close associates that are not former colleagues but may work in the same field, former professors, close friends with some standing and verifiable clout in the community, a priest, a rabbi, a nun...ya get my drift?
People other than your former employers can act as references and be of quality.
Employers mostly refuse to be a reference when honest comments would be on the negative side. Some are clever about not commenting while still giving a negative comment.
One of my former PR buds had a crisis of meaning and quit his job and went on the road with just a backpack and thumb. Later, returning to the professional world, he used his former boss as a reference, who repeatedly would tell his potential new bosses: "I don't have anything to say but can you ask Larry if he's found the meaning of life yet?"