Drybrushing is done to enhance the raised areas of a model, and should be as common a weathering technique as any, as it should be.
Usually, I'll airbrush a dustcoat overall to tie everything in on a model, then dust with pastels any areas that I think need more. Also, pastels are great for roadwheels, wheels, tracks, etc, as you can push the dust into the 'corners' of wheels, between tire treads, then dust off the excess that's above that, resulting in a very convincing look.