You can learn a lot about a culture from its mythology. The Danes were a fearsome, militarily powerful people. If they turned up on your doorstep in 1000AD, you would have done well to follow the advice of AC/DC to 'lock up your daughters, lock up your wife, lock up your back door and run for your life'. It would be trite, but nonetheless true, to note that the possibility of modern-day Danes (or indeed any of the Scandinavian descendants of the Vikings) inspiring the same response is ludicrously, preposterously unthinkable. And this holds true no matter how large a military force they were commanding - the shift is first and foremost in mindset.
Holger Danske still inspires Danish people though. The great Hans Christian Andersen wrote a short story about it. The Danish resistance group in World War 2 named themselves after him. But it does so because of the history. The story on its own strikes a strange chord that clashes with modern sensibilities. Even if this were the age of legends, I cannot imagine a story like Holger Danske resonating enough today to get started and spread through the populace, were it not already a famous story.
The notion of military heroism is largely an anachronism in the West. The ideal modern image is the soldier as a brave and tragic victim. They are noble when killed or injured. They are suffering when separated from their loved ones, and selfless in their sacrifices. Even the right buys into this narrative to some extent. We must 'support our troops'. You hear this more than that we must 'celebrate our troops'. The stories about troops that resonate are those of pathos. We want to hear about the man who died bravely on the battlefield to save his companions, not the guy who bravely kicked tons of enemy ass and lived unscathed to tell the tale.There's no shortage of stories of incredible bravery in Iraq or Afghanistan. But for some reason, you mostly hear about them in the context of soldiers who have died. The heroism is mainly there to add poignancy.
Holger Danske is old fashioned because it envisages a natural warrior aristocracy. In an age of radical egalitarianism, we can have 'heroes', but not a 'hero'. Because most people will never be truly heroic in their whole lives, the whole concept must be sufficiently diluted to cover nearly everybody. Today, you are a 'hero' for volunteering in a soup kitchen, or doing an AIDS fun run. What word, then, would you use to describe Simo Häyhä? Or Ben Grierson? Or, indeed, Holger Danske? He's not administering to the needy, he's not interested in being a glorious victim in a fatal last stand. He's interested only in kicking enemy ass on your behalf to keep the land safe for those of his countrymen without his courage, strength or skill. And that is what modern man truly cannot abide - the implication that nature has furnished us with natural betters, and we should celebrate and admire them, and be grateful when they lead our country to great achievements. They are not servants of the public. They are kings, ruling over us by right of their strength of character and proud lineage.
We live indeed in a Kingless age.