The definition of Quirk is a definition, no matter how you want to apply it. It is, "Something that is strange and unexpected; A sudden twist, turn, or curve." It isn't necessarily my definition but I do love it and think that any golf courses that have some quirk are all the better for it.
My design preference, though (which is akin to one's philosophy, which makes every architect different, and which is the reason this site is so active for two decades now, by the way), is that Quirk should come naturally, and isn't manufactured just for creativity's sake. To me, Quirk happens when an irresistible force runs into an immovable object. In other words, when a feature is absolutely necessary in the design process and its form is altered because of an immovable object (a road, a real building that can't be avoided, a topographic feature compromised by a property line), then it is a Quirk that wasn't expected. In other words, the architect came up with a great design solution to a problem.
When it is not, and it is just manufactured, it just isn't a Quirk. A feature that is completely manufactured based on an architect's creativity may be a great feature, it just may not be Quirky. My point in all of this is that people apply the term "Quirky" a bit too loosely when funky, or innovative, or just "cool" are probably better terms, technically-speaking. Quirk is just not a catch-all for anything that may be inspiring or thought-provoking.
Tom makes my point when he says it is crazy to design something that is Quirky. Just let it happen. Archie as well when he says that if one goes out intentionally seeking Quirky, it may blow up in one's face.
Again, I do love Quirk, so I'm not dismissing it and I try to create things in my work that many here would call Quirky. I just would rather call those features funky or innovative, or different, etc.
By the way, you are all getting sucked into needing my book when I am done because if you think this Quirk exploration is fascinating, you will definitely get riled up about the other chapters. The one on Fairness comes to mind.