Planetary gears need a stator. It can be done, i.e. have the gear box attach to the side of the barbeque, but that'd be way more expensive to fabricate and it w

Planetary gears need a stator. It can be done, i.e. have the gear box attach to the side of the barbeque, but that'd be way more expensive to fabricate and it will be BBQ-specific. Here however - one inner gear, one spur gear and a rotating shaft and that's it. Stupid simple and it works.