I see quite a few people on that forum that recognize they do have meanings. Pre-reqs, carrying capacity, holding breath. At the very least, I don't see any of them claim its arbitrary. I don't have any references available to me, but I've seen charts that did it for strenght. Heck, strength is probably the easiest to see for me because I can just set up someone's strength to see carrying capacity in NWN2. So, at least strength readily shows its meaning through carrying capacity as that is far from an arbitrary ability and can be directly compared to real world strength.