Like why are the bars only vertical? Do they make any that have horizontal AND vertical bars? Spaced close together so the baby can't get any body parts trapped in it. It just seems like a superior design but I can't find one like this anywhere.
If the bars are too close together for a baby's limbs to get trapped, they are also too close together to allow for proper air flow. Not to mention the climbing out issue aleady mentioned by others.
Cribs don't have horizontal bars because that is NOT a superior design.
When the child gets old enough to climb, having horizontal bars is the same as giving them a ladder to climb out.
If you are concerned about arms and legs sticking out, you can buy a mess crib bumper. http://www.amazon.com/BreathableBaby-Breathable-Mesh-Liner-White/dp/B0013FGWD0/ref=sr_1_1?ie=UTF8&qid=1362184283&sr=8-1&keywords=mesh+crib+bumper