While cast wheels are lighter, I've always felt manufactures should offer heavy duty cast wheels on adventure bikes, at least as an option. They might be as heavy as spoke tubeless wheels but will remain true and be easier to maintain.
They would be ideal for those who don't take their big adventure bike off road which are most owners. I would prefer them on my Moto Guzzi Stelvio and V85TT because while I spend a lot of time on dirt and gravel roads I don't take these bikes through the woods or up rutted, rocky, Jeep/atv trails.
BMW has offered GS's with both cast, as well as tubeless spokes for "heavy duty" use, but I never saw mention that the cast wheels were any tougher than the soft cast wheels on their road motorcycles? That has changed because on the 1300GS they offer 3 choices, cast, spoke, and forged alloy wheels which are tougher than the cast ones yet still very light.