Do you approve or disapprove of Michael Moorcock opening his multiverse
up to other authors?

He has allowed numerous authors, including Norman Spinrad, Brian
Aldiss, Neil Gaiman, Nancy Collins, Tad Williams, John Harrison, James
Sallis, Storm Constantine, etc., to write with his characters and/or
with stories set in his various worlds.

Does this tarnish/diminish Moorcock's creations or expand them? I ask
because often the complaint with great writers such as Robert E Howard
is that their work has become tainted by some much hack writing in the
name of the original. Is this a risk or is it managed?

Cheers,

Thomas