Remember when "Pure Swordsmen" didn't exist, and anyone who carried a Sword was automatically a Swordsman. Then King came along, whipped out a Sword, and boldly proclaimed he wasn't a Swordsman, subsequently handing the Zoro fandom an L, more than a decade in the making?
Twisting panels context to feed your own narrative??
King never called him a swordsman because he didn't feel like sticking to traditional means.
The context here is to use anything to win.
In below panel, king was using sword but then suddenly switched to punching zoro
It's after this zoro goes on saying - you never called yourself a swordman. Have it your way"
But the context becomes clear when zoro further says - I might be willing to BITE your throat to because I can't afford to lose"
The context here clearly is about doing anything to win the fight - using cheap tricks as well which go against swordsmanship code/theme underlying wano samurais. That's why king never called him proper swordman.
But in one piece haki is integral to swordsmanship and many of you distinguish it from swordsmanship to put shanks over mihawk which was headcannon