Seems to me that you're the one that still don't understand.
The placement of those buttons have zero impact in this discussion. Greed and Disenchant being next to each other refers to the roll PRIORITY. If a single person or more rolls need on an item, only those who rolled need are tested against each other for who wins. If people either press greed or disenchant, they are both counted as equal on the rolling table. Ergo, Disenchant = Greed.
That disenchant button is there for a reason. Because not everyone has an enchanter. Enchanter is this profession that unless you're an enchanter yourself (or have another character that is in BoE's case) or someone else is in your party, you have absolutely zero ways of obtaining the materials needed to obtain enchantments. This is the only profession that causes this issue for material gathering.
The disenchant button, is to allow everyone an opportunity to get them, and this is for fairness, because otherwise, Enchanters would make a HEAPLOAD of money since only them could provide the materials unlike all other professions that could work only for tip at best, which will result in everyone making an enchanter, and it will destroy the enchanting economy entirely because everyone will enchant their own stuff. Which coincidentally might provide inscribers with a new market making a buttload in vellums, but i'm going astray here.
That is why you don't need on stuff if you're an enchanter. Don't be that guy. Everyone has a right to a chance at getting enchanting materials.