It says you don’t want loops to sound unnatural. Yes I do! That’s not cool Steinberg. Leave the aesthetic advice out of it.
I don’t see how this quote in my WL 8.5 manual: “Very short loops that cover only a few cycles or periods can almost always be found but may sound static and unnatural.” is in your manual any different? No qualitative opinion about ‘unnatural’ IMO.
Read this:
“A long loop sounds the most natural and should be used whenever possible.”
Ah, you’re right. For most uses, I think it’s still a valid statement… 
The first sentence is valid. The second sentence is stupid.