"We only need new WCA delegates if there is actually a competition without a WCA delegate.
In that case you have to ask a recommendation from an existing WCA delegate who knows you very well.
If you are in a new country then you may need to travel to meet with an existing WCA delegate, or ask an existing WCA delegate to travel to you and make a recommendation after the competition.
If that is impossible then please contact me by e-mail to see how we can solve this."
Here's the quote in its original context: http://worldcubeassociation.org/foru....php?f=6&t=439
The reason -in my eyes- is likely the orientation of the piece in question that has the sticker on it. Like when you are solving a 4-color mastermorphix the small corner piece that sits in the center of each color can be rotated wrong, resulting in the puzzle not being solved and you having to do another sequence of moves to sort it out.
You don't see this while solving because there is no up or down to be seen, however suppose there is a sticker on it of which you KNOW the bottom is facing a certain color, then you'd know the piece was rotated incorrectly were it facing another color. As you see this happening while you are solving you can take countermeasures and correct it and thus you MAY have an advantage over other cubers that don't have this sticker because it saves you time.
The fact that only one sticker max is allowed on any and all cubes, I think, is that they have to make a sweeping rule about this, otherwise as the Dutch say "is het einde zoek". Roughly translated: you can keep making exceptions for this cube, and exceptions for that cube, and you can keep doing this every time a new shape cube that is entered in a competition comes out. Very time consuming, and very annoying to adapt the rules all the time. Hence the sweep.
I could be wrong, of course, but this is why -I- think this rule is there.
At Austrian Open 2011 the delegate had problems during his travel so he only arrived in the middle of the first day. The organisers were informed about this so in the beginning of that day Ron was called and he nominated an experiences competitor as delegate for the time the actual delegate had not arrived.
I don't think such a situation should be in the WCA regs. It should be obvious that the board should be contacted if no delegate is available or that a delegate should contact the board if it is clear he can't male it.