Why do audiophiles shun feedback in amplifiers?

I've owned several very highly regarded tube amps. Some of them allowed adjustment of the amount of negative feedback. I've always found some degree of feedback improved the sound...more realistic with tighter bass, dynamics, better defined imaging, etc. I have found amps with less or no feedback sound loose and diffuse with less dynamics... I know you should design am amp with excellent open loop gain before applying feedback. I can see the use of no negative feedback for low level amplification (eg, preamp and gain stage of CDP or DAC). So why this myth perpetuated by audiophiles and even many manufacturers?