There’s a reason - most of those are manipulated images. Sure, several look pretty neat. But ultimately, I am far less impressed with enhanced/manipulated/”constructed” images than old-school composition, exposure, f-stop know how.
That's possible, of course, but I would think a contest would be explicit about allowing that. Or do you know for certian? It would not surprise me if some modern electronic cameras were able to produce such images.
Now that I went back and looked, I notice in the caption for photo #9 it says, “Kingham combines 23 individual stills to convey the excitement and dynamism of August’s Perseid meteor shower.”
Ah, well. So it seems I’m not completely obsolete after all! ;)
Ansel Adams would “dodge and burn” ( http://en.wikipedia.org/wiki/Dodge_and_burn ) when making a print from one of his negatives. This is also manipulation as he was changing the print to be what he wanted it to be rather than what he would have gotten from a straight print.
The computer makes manipulation easier, but photo manipulation has been around for a very long time.