I think wrt T206s, uniqueness is part of it, as is a desire to know more about the printing process. For all its popularity, very little is concretely known about the production of T206s. I suspect the uniqueness part is emphasized because there are so many T206s floating around out there.
Of all the thousands of Dode Paskert cards, how many look like this? For me, someone who loves T206s and is not a low pop high grade collector, this kind of uniqueness is much more achievable and far more interesting.