This is hard to say; is it simply expectation bias? Because some instruments have elements with wacky harmonics, like bells, metallophones, xylophones, Jamaican steel drums and such. Notes do not have a fundamental which coincides with a harmonic of a note one octave below. That's just how the instrument sounds. If a piano reminds us of a metallophone :) then we conclude that it's awful and out of tune. Still, even that is appropriate to some genre, or for comic effect. A western saloon bar calls for a detuned piano. :)