Spider God's Bride is part adventure and part campaign setting, probably one of the better iterations of Sword and Sorcery I've seen for a while. Sheoloth, is I admit, something I am not really enjoying as much as I did Spider God's Bride but I'm commited to that particular project and Matthew has a lot of faith in it.
Creating a new setting from scratch is a mammoth undertaking, something which I don't think a lot of people truly know just how much work is involved in something like that.
I've worked, for the last year and a bit with Tim Brown on the spiritual successor to Dark Sun and Dragon Kings is a phenomenal amount of setting information. It's presented as a world book that's completely system-agnostic and that was an incredible experience to see evolve.
Glorantha had a team of people working on it, and now that setting is elsewhere with Moon Design iirc, who have handled the HeroQuest iteration of it for ages and ages. Having done the Glorantha Guide and so on.
I'm not sure what happened with Elric, because I've never really been into the books beyond Michael Moorcock's original works - never got into the RPGs that followed.
So making a fresh brand-new Legend setting would require a bigger writer pool than we have now, or more hours in the day than Damon and myself could comfortably dedicate beyond the projects we already have.
In the end though, as much as I would like to see something unique and interesting to Legend the person that people need to convince is Matthew.