Julian,

Some folks want more of the pattern exposed to the eye than others. There are simply some makers who do things differently so their work stands out in a crowd.

The edge thickness will make no difference, the acid etching is not that deep in most cases. But inattention can cause accidents that might be the source of legends about this stuff. It's very easy to put an acid resist on the edge or a half cm up the blade to protect the previously polished steel. So the edge would be in no technical danger at that point.