Musashi lived almost half his life in the Japanese "Warring States" era. It is said he participated in the losing side of the battle which ended that era - which would mean he did, in fact, have experience in a large-scale battle. Not that he would need it to know what the hell he is talking about. (60 duels proves he knew a lot more about combat than pretty much anyone he came in contact with, and pretty much everyone he didn't meet as well.) He also said nothing about the yara or naginata... although he did defeat a yara specialist in a duel.
However, I did come across this when reading a treatise on Musashi:
"Likewise, halberds and spears were specialized weapons, primarily for fighting in formation and especially for dismounting and anti-cavalry actions."
Which sounds close to exactly what I've been saying all along.
The more you guys talk, the more obvious it becomes that you're actually spear fanboys (which I had no idea existed before a few weeks ago) and want that particular weapon to be overpowered. And you base this on a skewed and inaccurate view of history.
(No, the spear isn't "king of the battlefield" and no, Musashi never made a statement about yara or naginata being the best battlefield weapons.)
I can only hope any mods who read this see your opinions as the biased spear-worship that it has become.
P.S. as for your mini-rant about daggers: they're not designed as a primary battlefield weapon, while swords/axes/spears/maces/bows/crossbows etc are all considered candidates for primary battlefield weapon. But to quote you: nice try.
Are you serious? your "quote" is from some random person on the internet, NOT Musashi! http://sebastianmarshall.com/why-does-musashi-talk-about-swords-so-much You're actually using a random internet comment to pretend to have historical credibility!
"The more you guys talk, the more obvious it becomes that you're actually spear fanboys"
The more you talk, the more obvious it becomes that you don't give a single care for actual history, choosing willful ignorance and random internet comments over actual historical figures who actually fought with these weapons in reality because they disagree with your armchair deductions.
Meanwhile some actual quotes from people more qualified than anyone alive today (and didn't primarily have knowledge of unarmored duels):
From Paradoxes of Defenses:
George Silver, who actually trained nobility to fight in both duels and battle describes polearms of the perfect length as having the advantage over "the two handed sword, the sword and target, and are too hard for two swords and daggers, or two rapier and poniards with gauntlets "
From the Konungs skuggsjá, an instructional manual for the son of Norse nobility:
"In battle a spear is worth two swords"
Actual period sources and artwork depict spears (and later, other polearms) being overwhelmingly used as the primary weapon for the warrior elite of medieval Europe.
Knights on foot used spears against other knights and common infantry... not just as or against horsemen:
EVEN FOR DUELS ON FOOT.
And even samurai. And no, these aren't primarily "for cavalry".
There was even a yari made for Samurai police (who had swords) to be used inside... Definitely an "anti-cav" weapon right? Or maybe because spears have superior leverage and speed of point over swords.