Why not give drone pilots a separate set of wings, as the questioner recalls being done for helicopter pilots?
Short answerNo definite reason is given. One tentative suggestion is that helicopters constitute a separate specialty while other aircraft are grouped as fixed wing.
NotesThe follow-up asks whether a separate badge could distinguish drone pilots, using helicopter pilots as a comparison. No definite explanation is established. The tentative suggestion is that helicopters form a visibly different flying specialty, while crewed and uncrewed fixed-wing aircraft can remain grouped together.