Some people I follow do a variety of artistic medias and storys and such. I can easily say I only Like some aspects of their work and wish to only follw their (eg) Fashion Folder instead of everything they do.
There are people that don't utilize their folders for all their work. Who's to say the folder you hypothetically watch will ever have anything else added? If you don't like the artist's entire works, add their profile to your favorite websites and check it once and a while instead.
It would end up being too complicated and extremely limiting. If you only watched a single folder and happened to go on that artist's page, it would be a shock to see other things that may sour your opinion of them.