... rather than into the climbing harness tie-in points? Other than because the Harness Manufacturer tells you to... I was the Harness program manager at Black Diamond for 10 years - perhaps I can explain the difficulty of explaining this rather nuanced detail. Brings to mind Noel deNevers Rule of Complexity... I am one of the people that has studied this particular issue in extreme detail: 1. There is a significant amount of personal preference in this, but as the author of the instructions, it is my job to recommend the way of using it that will work for the most people. Among other factors, people greatly prefer doing it the way they have always done it, and inflict their personal preference on the new people they mentor. 2. When you are standing, if the harness fits you, the harness tie in point and the leg loop cross strap are not adjacent. They will be about 4" apart, depending on your dimensions. When you are hanging in the harness, you are in a sitting or semi-sitting position, and the two tie in points are necessarily adjacent, and share the load. Ideally, the load is shared 60-60 - if the load is 100 lbs, then the waistbelt gets 60 lbs and the leg loops gets 60 lbs... 20 lbs total lost to vector addition. 3. The belay loop is adaptable and loads well to both a standing and sitting/hanging situation. 4. The harness tie-in points are reinforced to deal with the wear and tear of rope-on-tie-in-point interaction. The belay loop is stout, but not reinforced and would wear out quickly if the rope was tied in there... here I assume sport climbing where multiple falls and hanging in the harness is an everyday occurance. 5. Is this sufficient? Not really, this background information. 6. The system of having a belaying carabiner out away from the body 4"-5" makes the system better. More visible to the belayer and onlookers. More easily inspected and adjusted. Less covered by clothing. (Not a big problem in summer, definitely a problem in the cold. Almost lost Jenny due to this.) 7. The system of having the belay carabiner doing EXACTLY one very-important task makes the system better. 6+7. When the belay carabiner is clipped tight and rigid to the body, it is not visible, it is pinned in position, it is doing several things at once. Not ideal. Also, on some people, the distance from leg loop cross strap to waist tie in point is much larger and a large locking carabiner, thus VERY uncomfortable to deal with, and very rigidly held. 8. There are smooth rounded parts of a carabiner designed for the rope to flow easily over them. There are working parts of the carabiner with some sharp edges, which we do not want a loaded rope to cross. By holding the belay carabiner tightly against the body, we would be inviting the loaded rope to interact with parts of the carabiner that have sharp edges. (To me this is the biggest danger point). 9. In the USA at least, you are still welcome to do it however you want. But don't blame me!!!!