no real reason other than its using as minimal a component list as possible (its the kind of thing most people can whip up instantly from stuff in their house)
my soil retains more water than it should so plent new air holes couldnt go amis, lol
Later on ill be putting holes in much lower down the pot for some tight horizontal turns of the plant.
and finally because i didnt think of using clips, it really was i went in the kitchen and just grabbed whatever i thought would work.
EDIT: oh yeah and soil, they are only in that soil now untill i can purchase some coco, im changing my grow method soon.