User blog comment:Silver-Haired Seireitou/Sake Time with Sei - Shinigami and Hollows, Thousands of Years of War/@comment-1493741-20140420213920

Personally, I don't consider Hollows naturally evil, just a cog in the machine. The way I see it is that the Soul King set the universe up as it is, his power was great enough to create all of these things but not so limitless that he could maintain it on his own or have it lack restrictions of its own. Hence the balance of souls. The worlds he maintained are seperated, but are somehow attracted to the souls that inhabit each of these plains. One side having too many souls causes the other world to drift towards it, causing them to bleed into each other and wipe everything out.

The Soul is near eternal, having a great lifespan of its own that is rarely snuffed through natural means. So they're placed into bodies made of Kishi in one realm so that the Soul can feel like it has died and pass on to Soul Society, the issue being that through natural decay the bodies made of Kishi die far faster than those in Soul Society which would cause the Human World to come to Soul Society.

To prevent that the Soul King created Hollows and Hueco Mundo, a third realm that further shifts the weight of the balance. Not all souls go to Soul Society, many are left to decay and devolve, losing their heart and transforming into Hollows while the Hollows themselves devour numerous Souls. Left unchecked the Hollows would consume everything without end, and so the Soul King bestowed gifts upon the strongest Souls that lived in Soul Society, giving them the name of Balancers.

The Balancers were gifted with the art of Konso, allowing them to ferry Souls to Soul Society themselves. They were gifted with arts and weapons that allowed them to cut down Hollows so that their numbers could be culled, and the amount of Souls they devoured did not become overly significant.

The Soul King himself is a lynchpin, his power divied up so that the three-way balancing act doesn't just topple over. He has the power to bestow upon his subjects, ways to impart his will, but the vast majority of his strength is spent maintaining the universe itself. And so there he sits eternally, atop his solemn throne.

...annnd that got a little story book at the end there, apologies.

Basically I see the Bleach universe as a washing machine, its a broken down, barely working washing machine, but it still gets the whites down every now and then. There's a cycle, its haphazard and filled with holes and flaws. Essentially, the Soul King played God, but he's got a ways to go before its flawless.