Whenever I think of Up The Long Ladder, I think of a M0vie Blog review with a photo of a grim-faced O'Brien and the caption "I bet this was a fun shoot for Colm Meaney"
I can remember Roddenberry’s idea that the ship would need a space psychologist being relentlessly mocked in the 1990s, a criticism which (with more recent awareness of mental health issues) seems incredibly tone-deaf and idiotic.
Lance Parkin's The Impossible Has Happened (which notes Troi gets quite a bit of focus in Farpoint) noted the other writers didn't like her character very much either, so there's two reasons getting her little to do except "CAPTAIN I SENSE THE FROWNY PERSON IS SAD".