Reason 1: They taste good. Which should be enough on it's own, but isn't the full story.
Reason 2: They provide a bit of a fat and carbs injection into a vegetable and bean stew which would otherwise be short on those things. (I happen to see fat and carbs as a necessary part of nutrition rather than OMGDOOM :P)
Reason 3: They are deceptively easy to make. The basic formula is twice as much (white, self-raising) flour as (vegetable - Atora Light is the most common UK brand) suet with just enough water to hold the stuff together.
Reason 4: On the other hand, it is easy to add things to the basic formula to make your dumplings more interesting. Today's have dried chilli flakes and coriander; last week's involved a bit of added maize flour.
Reason 5: They bulk out today's portions of stew and help to ensure that there is enough left over for lunch tomorrow.
Reason 6: They qualify as an energy-saving measure, since they make an insulating layer over the top of the stockpot, meaning that I can have the stove at a lower temperature and still keep everything underneath simmering away.
Just a thought
22 hours ago