Is it not also possible that they get so much attention because they are genuinely interesting?
With that said, knowing Western designs of weapons is also extremely interesting. The progression of simple sword -> sword+crossbar -> sword+ crossbar + ring guard -> Rapier -> Basket-hilted sword says a lot about Western Martial Arts (aka: Fencing).
At some point, people figured out that grabbing the crossbar was more comfortable and more precise. So additional protections needed to be added to the top of swords (finger-rings / sweepings).
The full anatomy of the Rapier is astonishing. Every part of the weapon serves a purpose.
Even then, Rapiers were mostly status symbols for the rich. Weapons of War were far more simple and practical. (Well... not always: Landsknechte Zweihander == lulz. They probably discontinued that weapon because it was too expensive, heavy, and unweildly. But man, what an awesome looking sword )
On the article itself, while it's a nice list, it perpetuates some myths about the weapons in question (e.g. that katana was in someway superior to western swords -- high quality specimens on either side would probably be pretty closely matched), and has some fairly glaring admissions (e.g. the yari (Japanese spear) which was one of the most common weapons among footsoldiers for a good deal of Japan's history).
I guess Zweihanders were ultimately still "too short" for real warfare though. Practically speaking, by the late 1500s or so, people only used Halberds and Polearms (ie: English 18-foot Pikes and whatnot). So perhaps it is more accurate to say that Zweihanders were not "unwieldy enough". In any case, Zweihanders only saw use in a period of one century or so... from the late 1400s through the mid 1500s.
With that said, Pier Gerlofs Donia's Zweihander was 6.6kg (~15 lbs) and 2.15m (7 feet) long. Zweihanders definitely could go above and beyond 3kg.
As far as Yari, yes, that is the most glaring omission in the article. Fortunately, the Naginata (arguably a kind of Yari) has representation.
As for the disappearance, I think it had more to do with improving firearms making heavy armoured shock troops impractical, and armies becoming much larger things mostly composed of musketeers with relatively limited training (rather than the smaller armies of very well trained professionals like landsknechtes). The pike disappears fairly soon after, when infantry switch to using bayonets to ward off cavalry.
They don't "seem" foreign, they ARE foreign.
Unless you happen to live in the far east.