There's a lot of inconsistent coding on the UI and menu choice behaviour over the years.
Remember the magical map vendors from 2003? They will only sell you the KI maps that you don't have. When you purchase a KI map, the selection no longer appears in their list when you talk to them. But in 2011, if you talk to the cruror prospectors, they'll keep trying to sell you the same KI abyssites and temp items over and over that the game *already knows* you have LOL--forcing you to tab through pages of items the NPC will end up refusing to give you if you asked for them, anyway. :p
Or on some NPCs the default Yes/No confirmation will be "yes", while on others it will be "no" (even on things you'd probably always want to default "no" on...) And sometimes the "yes" or positive affirmation will be on top...and other times it will be on the bottom. :p
It's just lazy/inconsistent UI coding across many different dev teams...if no one complains they won't examine it.