It seems to be the "traditional" way of doing things. And I see how it makes it somewhat Ikea-like to flatpack and ship hives if they are cut that way. But other than that, any reason why a simple rabbet, staples, and glue; or splines and glue... pocket holes... etc. Are any less valid? Certainly in the 1800's if you were building something from wood, especially a box, you were either doing some sort of box joint, dovetail or clench nails. But is it simply done that way because it was always done that way, or is there some other benefit of which I am unaware?