I may be making a point that has already been made (and/or refuted), but
maybe the reason people age in Glorantha is that Glorantha is no longer
perfect since Chaos entered the world. Aging is simply a part of being a
Gloranthan, with some exceptions (heroic immortality, the culturally-static
Mostali and Brithini, etc.). Since Glorantha itself ages, it makes sense
that the mortal beings of Glorantha do so, as well.
Guy (Hoyle)
[Non-text portions of this message have been removed]