There's judgment and discernment, which involve developing and applying appropriate, intelligent standards. And there's personal preference, which doesn't always align with good judgment.
Aestheic judgments are no more subjective than other judgments. All judgment involves recognizing and articulating what's behind it.
By analogy, if I'm serving on a jury, I may not like the defendent, and be predisposed to want him in jail just because I find him creepy. But I'm bound to use my intellect, weigh the evidence, listen to the experts, and apply appropriate standards in judging whether he's guilty of the crime.
I judge the Crowley-Harris Thoth deck to be excellent. It's intellectually cohesive, no detail is arbitrary, the plan and meaning are integral to each card and the deck as a whole, the range of symbols--from the obvious to the most subtle--are consistent and meaningful. It has depth, and a kind of beauty. I respect it, and think it is miles ahead of most decks. Still, I do not like it.