Why teleportation and rareness?

Why do brains have teleportation? It is a problem get rid of brains or just the teleportation. Also why are crystals so rare? 1 crystal per world thats bull crap as soon as ya get close to bedrock in real life you would be finding a lot more than 1 crystal.

Midnight Owl25428 about Deepworld - Sandbox MMORPG, v2.7.0