I can definitely see value in a second set of rims for winter riding for those who live in places where studded tires are a benefit in winter. It's a PITA to swap rubber twice per year. Not a huge one, but if the truth be told, I have yet to install my studded rubber on my touring bike this season. The new fat bike is a part of that, but in several instances, I'd have been better off on the touring bike with the studded tires.
I had previously considered but never reached the point of pulling the trigger on a 2nd set of wheels for my studded tires. I still like the idea, but have a few other priorities ahead of it.