Bags I have a drying rack suspended from the ceiling of my utility room, next to the central heating boiler, so it's an excellent place for drying small items and airing larger ones.
I don't hang my 'smalls' outside, because they're, er, small, and I would only have to hang them up again to air when I brought them in. Double work. The same applies to any small items like socks and face-cloths.
Men's underpants to tend to be a bit larger, so they do sometimes get hung outside, depending on availability of space on the drying rack and/or the outside washing line.
So you see it is all to do with ergonomics and logic and nothing to do with prudery or delicacy 