You know, I completely spaced on the weakness of Julian's storyline over the course of the show.
However, by being able to hang around, Julian was a seasoned veteran by the end of Season 3 because of the budget cuts that eliminated a lot of the uni positions. I think by season 5, Julian, Asher and Danny were the longest tenured Unis.
His homosexuality did pop up every now and then, but exploring his homelife would have been way more interesting than the Danny/Vic/Corrine/baby storyline over the last two years. I guess the only explanation would be that since Julian no longer directly impacted Vic's life, his storyline was done. It would have been a good-ass subplot or stand alone episode though.