By taste we mean distinguishing pretty from ugly (or more subtly, distinguishing patterns related to that.)

Yes, there is an objective reality there. That's basically why some of us are artists and some aren't (that and self-confidence I guess).

It's what guides us when there aren't any obvious signposts around. Good artists, scientists and engineers use this faculty all the time.

Those who lack the faculty just stick to areas with lots of sign posts.