Dust bowls let you know you are in the right area. Most of the places I hunt, there is tons of sandy soil and other than letting you know there are birds nearby, they are not much more than a turkey track to me. When I see them, I think of being a likely place that birds will be later in the day, when it gets hot. Always has been when I have seen them there, but it may be coincidence. Not like I have seen tons of birds dusting though.
They are NOT deer scrapes or rubs that will likely be checked regularly though, IMHO.