Yep. That whole post is a load of...mythology, far as I can tell.
Yaarel is correct on one major point: the Germanic language family is most commonly thought to have originated in Denmark and/or the southern Scandinavian peninsula. However, he is miscontextualizing that point heavily.
Firstly, as I'm pretty sure Yaarel well knows but is choosing not to mention, the people speaking this ancestral Germanic language in Scandinavia were
not the indigenous Scandinavians, but descendants of migrants from the southeast carrying with them an Indo-European speech and culture. Germanic language and mythology is unmistakably Indo-European, and very different those from the
actual indigenes of Scandinavia, the Sami peoples, who by the way are still around today. Genetically, of course, there was a lot of mixing -- there always is -- and the Indo-European culture had been there for several centuries by the time it began spreading again as Germanic, but nevertheless calling it "aboriginal" would be like calling the culture and language currently spreading around the globe from the United States "Native American".
Secondly, he wants to draw a hard line between the material cultures of the Scandinavian Bronze Age and the Jastorf type. But Jastorf culture was at minimum heavily influenced by Scandinavian Bronze Age culture, and very plausibly represents an expansion of that culture. The fact that it lines up well chronologically with the reconstructed spread of the Germanic languages certainly seems to suggest that this is the case.
Thirdly, Yaarel seems to place some intrinsic value on which tribes spoke what and where "originally", as if the Norse culture we see in the historical record were somehow better or "purer" than the contemporaneous German or Dutch or indeed English culture. But just as much time separates proto-Germanic from recorded Norse as from recorded Old High German. And, note well, the amount is
well over a millennium. So to insist on calling it "Nordic" instead of "Germanic", as if the Norse were uniquely close to the ancestral culture rather than separated from it by the same gulf of centuries, simply commits the same error in reverse, and deliberately so, without the excuse of convention. Scholars of Germanic languages, by and large, know full well that "Germanic" is not a great name for the family. I've heard grumbles about it more than once. But it remains the convention; for whatever reason, the standard alternative "Teutonic" (which is in my estimation better) has fallen out of fashion. And as long as everybody knows what they're talking about, it's not a big deal. Notwithstanding Yaarel's frightful warnings, in my personal experience, there is no correlation at all between scholars I have encountered who use the term "Germanic" (100%) and those who subscribe to certain violent racial ideologies (0%).
Oh, yeah, and one last thing:
Runic writing is not original to the Germanic/Nordic/Teutonic language family. The script was adapted from those used by the Italic languages to the south, quite separately from and later than the initial spread out of the Scandinavian
Urheimat we've been talking about. Just to bring this digression around
marginally to the topic of the thread, but also undercut it entirely.