The product - art - is one thing; the attitude toward the artist is another. I doubt the weighing process is so rational in most of us, Uncle DaveO.

As an audience not a performer, I think the first stage is when an image or sound evokes a reaction in me (positive, negative, puzzled, or whatever) "touching" me enough to attract my attention. Otherwise, I swiftly forget this artist's offering if I notice it at all.

Second, I unconsciously weigh the comfort I feel about the source of this impression. I'm not appraising the work or the performer, so much as, again, my inner response to that work or person. If I'm prejudiced against some of the sound combinations or facial features, for instance, then the product has to touch me much more intensely, to keep my attention, than it would if I found the performer attractive or had a bias toward this particular style. (So if I were a white person enjoying Elvis more than I enjoyed non-white performers of the same songs, it might be because my prejudices made me subtly uncomfortable around "Them" despite the quality of their work.)

Finally, as I invest time and attention on a work of art, I start to shift my preferences as I begin to appreciate it more. I find reasons to like it, and I notice more about it. I grow. This is the only semi-rational part of the process.

But that's just my experience.