Historically, bread pudding is simply a way of using up old bread. There really isn't a set recipe, as one can never really be sure of what bread is available, unless one intentionally stales the bread just to make pudding. So to have a preset mix or kit to make it boggles the mind.
Much the same thing happens with brownies or pancakes. Most seem to inevitably reach for a boxed mix to prepare these things. A brownie is born out of a failed cake recipe, and look, it came out delicious. In this age of festive cooking, leave fear off the ingredient list, many of our much beloved classics are products of happy accidents.