I think that the general discussion here is if night caches are their own type then why not other "different caches". I think the difference between the types of caches are the way you find them. For example multi and tradional caches are different because you find multi caches with different stages and tradionals with one. Night caches are found normally using a flashlight at night with reflective markers.
It was braught up that night caches are so rare that there's no reason to make a seperate type. There's what I believe 2 night caches within a 20 mile radius of me. I'm pretty sure that there's little to none earth, Wherigo, and other types of caches in that same radius. Making a night cache type would only encourage more night caches to be put out which many people would enjoy.
And how many times has a geocacher gone to a mystery cache location in the middle of say a lake somewhere and logged a DNF just because the cache page said "cache isn't at posted location"? Since it would be a type, that would be a minimal and not really a problem.
Basically i'm saying there should be a different type because of HOWyou find it not what's involved in the hunt. Attributes are for what's invovled in the cache. For example, a 20 mile hike and a tool are involved in the cache and should be listed in the attributes. While you don't find a puzzle (not field puzzle) or mutiple stages found in the attributes.