This is the reason for face down default: When you are printing a multiple-sheet job, with "face down," the first page ripped is the first page printed. It is delivered face down so that, when you pick up a complete set from the output tray and flip it over, the pages are all in order.
You can change the setting to "face up," but when you take the completed set from the output tray, the pages are in reverse (backwards) order.
You can change the setting to "face up / reverse order" to compensate for that, but then, printing won't begin until the entire job has been processed (ripped). In the previous scenarios, ripping and printing can happen simultaneously.
None of this matters if an entire set can fit on a single sheet (i.e., a one-page/one-sided job, or a two-page/two-sided job). In fact, for a one-page/one-sided job, it may be preferable to print face-up, but not for the reason you might think (being able to see the quality in the output tray while the job is printing). The reason is that machines that image (print) on the upward-facing side of the sheet inside the print engine, then (by default) have to invert (flip the sheep) over to deliver it face down. To deliver it face-up, that inversion would not be necessary. That is a good thing, but again, not for the reason you might think (speedier printing, which is probably not true anyway). The reason is that less paper handling = fewer paper jams = higher reliability = more prints per hour.
So, if you want to change the default Fiery setting to deliver face-up, think it through: are most of your jobs one sheet per set? If so, go for it. But the more multiple-sheet jobs you have, the more you might want to leave that setting alone.