I will throw out this theory, since we dropping them, and propose something completely wild, but bear with:

the snarl is essentially a divine version of Darth Nihlious from the second Knights of the old Republic. It was created through the bickering of the gods in making the first world, and so became an entity that exists because of bickering and conflict. That leads to destruction, when the snarl destroyed the world after killing some Gods, because it had the contained essence of the Gods bickering over making the world, so being like Armus in TNG's Skin of Evil. After it wrecked the world, it had the bickering and destruction, which defines its existence or has at that point. So it must continue that work to survive.

Darth Nihlious has to feed on sentient life or Force life or whatever to continue His/Its existence in the story. Without then, Nihlious is impied to not be able to exist anymore. So how it goes with the Snarl, it must continuing feeding on the worlds because of how and why it was created. It also contains another element, that should explain the planet in the rift.

The snarl was made by the bickering and conflict in making a world by the Gods. That Gods' driven impulse of creating a world must certainly therefore exist and be present within the core of the snarl's being as well. It has been filtered partially through the bickering and conflict that lead to its creation. So the snarl destroys the world's in order to create new ones to fulfill its divine impulse while it also has internal conflict and bickering due to being created by that process -- the Gods bickering.

So, as the snarl consumed more worlds made by the Gods, it has absorbed more of the Gods agreement and working togetherness from the Gods doing that with each new world. That has been fundamentally changed the snarl along the way, but it has its bickering core to it, so it defended the new world (The rift world the snarl created) as a result of its own creation by bickerings of the Gods. The snarl might be trapped in not being able to change its nature from being the result of divine bickering and conflict, and so it has to follow that imperative, which it doesn't want to do. It may even have been making worlds as a way of fixing itself of the Gods's conflict, but needs the divine material from the other gods to order to shore that up, since it ended up killing one set of gods and it only, by its nature perhaps has only that one, since the strands of the world separated apart after the snarl destroyed the first world.

The snarl may actually desire to end its tortured existence and being unable to do so because it is a divine god being of its own, it is doing the next closest thing, and using the material of the destroyed worlds from the Gods material to make attempts at suicide or at freeing itself for only temporary moments of its own existence. But each amount of divine energy fades, forcing the snarl to devour more.

It still hates the Gods, since it was a divine hate, so perhaps the snarl cannot make itself tell the Gods that it may seek to terminate itself because it cannot self terminate, something it may have learned about only after killing the gods it did and the first world. So, it must attempt what it little knows, which has been bickering and conflict from the Gods when they made the first world. the snarl actually wants to go out. Also note that the dark one is purple and the snarl has usually been depicted with purple as a key part of it, alongside red and blue I think. so the snarl might be able to use the dark one to end its own insufferable existence and finally self terminate.

Assuming that the Snarl wants that and has been driving towards that goal. I think being in the Snarl's position as a way, that I might seek that, to self terminate.

So, yeah. It is a pretty big bit of crazy and who knows, but feel free to comment on my degree of insanity and crazy with this