Exactly. You couldn't have O'Brien, Rom, Nog act like a Romulan as Dax did "In the Pale Moonlight". You could have had Jake be comforted by anyone on the station after his father dies in "The Visitor" but it doesn't have the same impact as Dax. Or anybody striking up a friendship with Quark, Ferengi warts and all. Our "out-Klingoning" Worf. Eh, I like the character.