They tend to be set in their attitude regardless of enormous objective proof.
Subjective proof. There is very little objective proof. Objective proof would require either electrical testing that shows a change that correlates with known limits of human hearing and/or controlled listening tests. w.r.t. measurement, a few areas: high resistance from small gauge and/or excessive inductance or capacitance causing significant roll-off and wide-bandwidth amplifiers having instability, which for the most part has been "fixed" in newer designs. Either of these issues can be addressed with very little expense. Shielding can also contribute to reduced noise floor, but again, that is addressed very inexpensively.
On the controlled listening tests, they tend not to support the conclusion that there are reliably identifiable differences in the sound between various cables when the volume is controlled for. To this day, I am not aware of even 1 public, controlled listening test, conducted by a cable vendor. Not 1. You gotta admit, that is a pretty damning statement, especially in light of the challenges and the willingness to let the vendor control every single variable.
I am not advocating 18 awg zip cord, and dollar store interconnects, but while audiophiles like to talk about "diminishing" returns, based on the objective evidence, the reality may be "no" returns past a certain price point and that price point may be relatively low.