To truly understand this you have to think like a small snake. When you are a small snake, you have TONS of predators, so naturally you are gonna be pretty stressed out. Having a large enclosure will only compound this natural stress that young snakes are under. A smaller cage will make them feel more secure and less likely to have health problerms like not eating, etc. Not to mention a smaller cage is more practical with a small snake, cleaning it, finding the snake, managing temperature. Hope this helps.