Wulfram said:I suspect that if female dragonborn are too unfeminine they'll get ignored by many players, as well as the artists, so it's probably a good idea to give them breasts even if it doesn't make a huge amount of sense. They'll be of more use that way
I don't think the "female dwarf" issue really applies here. Nobody wanted to play bearded dwarven women because they looked like really ugly human women. Dragonborn don't look like human anything, and nobody who wants a human-looking character is going to play one whether they have breasts or not.