As for myself and I suppose for most if not all, this audio endeavor is not like some pharmaceutical that could save my life. I don't need or care about some rigorous peer approved double blind study to provide evidence that my chosen audio system and/or components may or may not be objective references. My audio system/placebo makes me feel good, and I'm not going to suffer a single bit knowing its only a placebo.
I agree. The kind of "bias" I am looking to eliminate is the one where I *think* I like something the best and someone helps me see I'm missing something else that I like better.
For example, when I first listened to some B&W bookshelf speakers at a store, I thought they sounded the best. A friend was with me and pointed out that they were rather on the "bright" side and that they could become fatiguing. He pointed out that I should pay more attention to the midrange, where the voices were, and to consider that as important. So, my "bias in favor of bright shiny highs" was eliminated and a different, more justifiable, preference (for my taste) took its place.
As you've pointed out, one doesn't need a double-blind study to mature one's appreciation of what's important.