For some their constant player may be a healer, or a DPS. Mine happens to be a tank. Although I may swap out moonkins for an ele shaman, or a priest for a resto shaman, I don't see myself replacing my tank with my 5-man. Since I don't want to "waste" any drops, it made sense to me to do enchanting on my pally since he'll always be there. Although JC is an OP profession, I was asking more along the lines of the type of profession(s) that you'd absolutely want to have on every 5-man run. Every toon having JC would be nice for the daily, but a JC doesn't need to be in the instance since everything can be cut outside.