I've first read about it on a more mathematically and scientifically inclined tuners page. It also described the effect that slightly untuned strings on the same pitch create a semi-chaotic effect which allows us to hear the tone for a longer amount of time, while raising the perceived loudness (caused by a very strong initial decay and a long linear decay).

There is a good explanation on Piano Acoustics linked from the wikipedia page you posted [1]

[1] https://en.wikipedia.org/wiki/Piano_acoustics