The save file format was changed in DKS, necessitated by changes to skills, equipment, the enchantment system, etc. All of these would have to be considered when converting the D2:ED save, with consideration for game balance as well as compatibility. Testing would require a fair bit of time, while the number of people who would use it is very low now. Shortly after release there would have been more demand, but most people who played the original release of D2:ED and bought DKS either started over to try out the remastered D2:ED or recreated their character in FoV. I would have continued with my D2:ED character into FoV if that was possible and then started a new game in DKS at the beginning, but it wasn't, so I just started a new character.
