Good question; I'm not sure. That said, none (literally none) of my PostgreSQL-using clients use psql, and they're somewhere between amazed and horrified that I prefer it for working with the database.
I'm not against GUIs, but it seems to me that psql has all of the advantages of the GUI administration tools, and then some.
I'm not against GUIs, but it seems to me that psql has all of the advantages of the GUI administration tools, and then some.