I'd never really thought much on the tribes in that way, but I think you're right. I share my smallholding content on a Facebook page and recently switched to using the natural medicine tribe link rather than the steemit link, as the tribe interface should be more relevant all around. Because people can now sign up for an account via that interface I think it could feel more approachable for people whose interest lies in that area, without being put off by trying to find their interest amongst everything else on the chain. Also, they should be able to avoid most of the bickering and politics which might put them off.