I can only guess that it's a clipping issue, but IMO it'd still look better on your hip than on your back. Like, entire armor sets have clipping issues by themselves so I don't think it'd be a big deal if rapiers/maces/longswords clipped through characters' arms a bit.
I think so, too. I don't think clipping issues can be completely avoided, and I would prefer if my bard could wear her rapier properly, even if this would mean it would clip through her arms or legs a bit.
I get why there are no scabbards etc. for weapons though, the animations for drawing a weapon would become quite complex - or the weapons would simply go through them.
It does look funny if weapons are somehow magically glued to the characters, but that is something I have learned to ignore in games 😄
