I suspect that the informal nature of a talk might mean that one can describe things at an intermediate level of detail (“and so do this and that”) that would look strange in a more formal paper, and so writers feel that they’re stuck with either going into a full level of detail (which would be too much work to do for everything) or else saying “I’ll leave this as an exercise to the reader”… even though going into some detail would be more useful to the reader.
I suspect that the informal nature of a talk might mean that one can describe things at an intermediate level of detail (“and so do this and that”) that would look strange in a more formal paper, and so writers feel that they’re stuck with either going into a full level of detail (which would be too much work to do for everything) or else saying “I’ll leave this as an exercise to the reader”… even though going into some detail would be more useful to the reader.
I agree so much, I have to do it in writing.