So true Martin. Doing exercises are also an opportunity to explore and be adventurous - occasionally it might be instructive to push boundaries and even break the rules you are practising to see where it leads, only occasionally mind if you are still learning, because the rigour is instructive and essential too. There is no harm done by refusing to be bound up now and again though imv...a bit like flexing one's imagination, which also needs practice.I thought that's exactly the point of such excercises?!
........ But just honing your craft for the sake of improving, with no goal or pressure of sharing or preserving that work has been done by most artists that ever lived... it's just part of practice, and that has nothing to do with any platitudes imho.