Seeing as this is photography for geeks: Colour temperature is exactly that, a temperature.
Things glow when hot, with the colour of the light depending on the temperature and the material. When you say "a colour temperature of 6200 K" it means the light is the same colour as that emitted by an ideal black body at that temperature. It's no coincidence we perceive colour temperatures around the high 5k to low 6k as white, because the surface of the sun is around 5800 K.
In practice vast majority of scenes are not illuminated (directly) by a blackbody source, so for white balance purpose its inherently crude tool to achieve a color look, and often there is no "correct" color temperature setting for a scene
Yup, of course. That's why software like Lightroom usually has a "tint" slider next to their colour temperature slider. It's just that "colour temperature" seems like a pretty weird turn of phrase (and the article seemed pretty befuddled by it), so it's worth knowing what it actually means.
Things glow when hot, with the colour of the light depending on the temperature and the material. When you say "a colour temperature of 6200 K" it means the light is the same colour as that emitted by an ideal black body at that temperature. It's no coincidence we perceive colour temperatures around the high 5k to low 6k as white, because the surface of the sun is around 5800 K.