Why should I use a Decoction mash instead of a Single Temperature Infusion mash?

Most all-grain homebrewers actually use multiple infusion mashes, usually with two steps (amylase rest and mashout).

My experience with decoction mashes are that they are a lot of work, lead to a slightly darker and slightly drier beer that keeps its hop aroma for a longer time, as compared to infusion mashes. I attribute the hop aroma issue to driver off oxygen in the boiled portion of the decoction, resulting in less HSA.