We need a Pointing CONTAINMENT Thread.
When it comes to etiquette, some things started so long ago or for such an obscure reason, that it'd be hard to find out the WHY behind so many things we take for granted. There are some authorities on etiquette like Miss Manners if you're 100 years old, but for the most part these things are handed down through generations. You simply can't drill down and constantly ask "why" or just assume it's not a thing if you haven't heard about it. No one cares if you have a great reason why it's "stupid."
Pointing is considered rude in many circles and cultures, not just in the south or in high society. For example: I grew up in a bad neighborhood in the 80's and 90's and I certainly wouldn't go around pointing at people there either unless it was purposely aggressive. The drug dealer down the block thinks you're pointing at him instead of the thing near him, and you're likely in for an unpleasant next few moments.
If you don't know this piece of etiquette or disagree with it, it doesn't make it any less true. If your job is to milk people's expendable income from them, it behooves you to take the least offensive line possible with them. (until tilting them is the better path)