Considering the European House Sparrow is not native to the Americas and was imported by a bunch of Shakespeare loving idiots with prose for brains (along with the European Starling) and the damage they have done to native bird species by driving them off their nests and using the sites for themselves, I'd say he's doing native wildlife and those that enjoy them an admirable service.
If you want to promote your feeders as a way to not feed sparrows then just say so. Besides, if people truly want to keep them out, they'd build their runs with hardware cloth that doesn't allow the smaller wild birds that carry diseases and parasites into run/coop; thereby negating the need for a clever feeder like you make.
