My understanding is that LOS was commissioned by a British arts organization. It was their idea for him to write a new work. I suppose he could have turned it down, but he decided to take it on (or it was suggested he try it, depending on how cynical your point of view is). It's actually not that commercial of an idea. Brian has been working on another album of pop material in the studio, but as of yet, hasn't begun formally recording "Lucky Old Sun." To me, that indicates he and his supporters find less commercial potential around the project. Plus, there's the fact he's doing a big tour of Europe in the middle of creating it, instead of staying home and finishing it and/or recording it.
"TLOS" was commissioned by The South Bank Center as part of its opening season after a major refurbishment. If you'll recall,
Smile wasn't "formally recorded" until some two months after the live premiere. As for touring instead of working on it... time will tell, that's all I'll say.
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