By the way, if I remember correctly, HP-UX, at least at one point, only allowed one open descriptor for a particular network device to be put into either physical promiscuous mode or "SAP promiscuous" (accept all packets, rather than just packets to or from a particular service access point, e.g. Ethertype or LLC SAP or...) mode (I forget whether it was one or the other or both), which also causes a problem with having the main screen display traffic statistics by capturing and discarding traffic.
I no longer have root access to any HP-UX machines, so I can't test that. (It would be Truly Nice if Oracle/HP/IBM provided isolated Solaris/HP-UX/AIX virtual machines, for which free-software developers could request access including root access if necessary, for build testing and run-time testing.)
The main OSes on which people are likely to run Wireshark with a GUI don't have that issue for regular network interfaces, but you *might* still have people running Wireshark on their Solaris/HP-UX/AIX servers with DISPLAY pointed at their desktop/laptop machines.