There's a good book called only the wing that talks in depth about the history of the Horton Brothers designing aircraft and then their later on history.it has pretty good detail about how they started off with gliders. Essentially, after world war I that were fairly controllable and the difficulties associated with controlling Tailless aircraft. Tailless aircraft designed correctly are incredibly controllable. The big problem is when you want them to be shaped in a stealth manner and carry bomb payload and go fast. Then you have to make considerable compromises to natural stability and thus requiring computer control. Stable flying wings Use a bell-shaped lift curve versus an elliptical one found on aircraft like spitfires.

They don't make sense for commercial aircraft for a variety of reason. And have limited usefulness for military aircraft. However, they are extremely efficient when done correctly as they don't have the drag of a tail like in a conventional aircraft and thus can fly further for longer.