I think for it to be a clinical problem, there needs to be a struggle. Like, in my particular case, I enjoy staying up late. The neighbors are quiet, my housemates are generally falling asleep, and I've got an hour or two to myself to knock something out or research something I find interesting. There's no struggle though; I found a job that lets me work an evening shift and I couldn't be happier with the state of things. I feel like if I needed to get up regularly very early in the morning, there would be an adjustment period and then I would equalize on a new normal.

That certainly fits the description of "night owl," but I don't think there's anything clinical about it. My particular manifestation is more of a lifestyle choice, and based on what I observe in the tech field I'm hardly alone in making this choice. Folks who do have a sleeping disorder causing night owl tendencies to manifest (especially when they'd prefer, socially, to rise early) are in a different boat altogether, and I'm... honestly not qualified to classify them. It's an interesting space.