In theory, yeah it would be nice and there are some artists that offer up their track stems for devices such as NI's F1 Remix Deck. However, there's no chance that it will become a norm for artists to simply start supplying the stems for all their tunes for reasons such as the previously mentioned copyright issues in addition to royalties management. To add, if the particular stems utilized a sample that was cleared for a single track only, that in itself would open up a can of worms.
That said, there's nothing stopping you from deconstructing the core components of a track and DIYing your own stems from it...
Would it take off? dunno because I don't think many producers would be up for it due to copyright
