fearsomepirate
Hero
As someone who has never really been able to understand any published adventure I've read, and who has been frustrated in every published adventure I've ever played, I am inclined to disagree. The amount of work needed to make a published adventure make enough sense to me that I could run it is vastly more than the amount of work I do prepping homebrew adventures. Obviously just talking about my experiences, others' are almost certainly different, YMMV, offer void where prohibited by law.
I personally find published material saves me enormous amounts of prep time. In fact, I don't really do a lot of prep at all.