Zanussi ZWG1120M: Main Wash Only 30

I don't quite understand the point if this cycle... other than to do a separate pre wash? But it doesn't spin so that wouldn't be very useful. The manual states it is for "clothes that only need the single wash" whatever that means? That probably explains why I've never seen it on any other machine before. Anyway here it is freshening up some new tops with half a cap of softener, normally I would use the rinse cycle but this seemed a reasonable way to test the main wash only.