Not as in "the constant friction from thick denim wore through the fibers of the cotton." Not even as "poor laundry habits torn through the seam of my underwear." I haven't even worn the damn things yet, and they have a hole! A hole by design. Why?
What purpose could this possibly serve? It is, by far, not a common feature in girls' underwear - in fact, it can be rather silly looking, and the small hole exposes a tiny fraction of butt-crack that cannot, in any way, be considered "Attractive." Is it a signature feature, limited only to a specific brand? Is it a radically new design feature that meets the previously unconsidered demands of customers? Is it some weird in-joke that only an underwear designer would get? I present to you, my scientifically-minded readers, several hypotheses I have developed on the subject.
People who like to pretend to be animals
I hesitate to refer to such people as "furries" because it's not necessary that they be attracted to anthropomorphized animals. It is enough to enjoy the aesthetics of a human with a tail, no? The mysterious underwear hole is placed in such a way that it perfectly aligns with the human tailbone; exactly where a tail would emerge, should humans have them. I personally suspect the market for such a feature in undergarments to be a rather small percentage of the overall underwear-seeking market; however the addition of the "tail-hole" does not impede the function of the underwear and most people seem not to question it.
The explanation that instantly leaps to the mind is that of - ahem - "easy access". Most people will see girl + underwear + hole and come to a conclusion that probably involves a phallic object entering said girl through the panty hole. We mustn't, however, forget that perhaps these punctured undergarments are modesty devices that will hide a girl's privates while still allowing the necessary, er, manipulation of her rear end. Two such situations could involve airport security, or a visit to the friendly neighbourhood proctologist.
Boys who wear their girlfriend's panties. Backwards.
Following from the phallic example above is consideration for a girl's male "friends." Perhaps there is a market for girls with boyfriends who enjoy wearing her panties? We can tell from simple observation that there is not enough space afforded in flimsy women's panties for an average male's package. Clearly, the solution is to remove the package from the envelop. The only problem with this hypothesis is that the underwear will have to be worn backwards to be used in this way.
Seamstresses who don't know how to make darts
A rather mundane explanation - not to mention a confusing one - is that, perhaps, the seamstress or designers involved in the creation of these underwear do not know how a dart works. It is fairly common knowledge that the female body is curvy, especially in the hip and buttocks area. Building clothing to fit these curves without sagging and stretching generally involves the application of darts in the fabric. Perhaps, when presented with an unassembled panty ready for darting, the seamstresses merely tilted their heads to the side, allowed a string of drool to descend from their lips, and then decorated the edge of the would-be dart with lace and a button.
Super wedgiesPerhaps the whole thing is the result of hours of maliscious scheming on the part of school-yard bullies. It is fully within the realm of possibility that said schoolyard bullies planted an agent in the ranks of underwear designers of a prominent underwear brand, solely to craft undergarments that facilitate the giving of wedgies. Stronger seams for reliable grip; stretchy fabric that will uncomfortably drive itself into every crevice; and finally: a handy finger hole for improved grip and even suspension.
???My dear readers: perhaps you have some suggestions I've overlooked? Maybe there is an underwear designer in your ranks who can shed light on the issue.
Maybe my problem is that I'm assuming the panty hole exists for a logical reason and wasn't introduced simply for the fun of it.