The issue (and I repeat more plainly) the people who are really asking for DS in 5e are not the 4e crowd so suggesting a 4e book is not the solution. Furthermore such crowd would likely be far more dogmatic about the rule changes.
Not to pick on
@Coroc, but I quote part of his
post which might illuminate what I've been trying to say over the last few pages.
Bold emphasis mine.
Coroc, Zardnaar and others like them are the type of people who would be asking for a 5e DS, so your 4e game IS but
a wussified version of Darksun not true to the originals (
EDIT: to them. In case it was not clear)
, and your suggestion that they pick up 4e DS is unhelpful at best.