Well, once long ago... before Kunark came out... folks asked similar questions about all the planar armor stats. Verant's response was "We want the players to have well rounded stats"
Now that the game is venerable, we all know that some stats are useful and some aren't, depending on your class. If things were like pen and paper D&D, all stats would actually be useful for all classes, but alas, this isn't the case, as we all know.
The only reason now to get a set of the original planar armor is for bragging rights, IMO, since there are SO many better and easier to get alternatives. (Except perhaps the BP/Legs and some select items)