Come to think of it Alex, you haven't actually said which objective elements of the design were poor; I'd genuinely be interested to hear that if just for the sake of learning about card design but moreover, it would be an irrefutable point you could make in this debate.
Objectively speaking, the art on the box is the kind of art you see from someone who begins learning Photoshop for the first time. The text effects are straight out-of-tutorial basics, the typography is all over the place with no consistency, the layout pays no attention to proper spacing and padding, and the original back design was so awful that all the details were blurred due to the air-cushioning (admittedly this is now fixed, and it was clearly a huge issue that warranted a fix in the new versions).
Yeah it can look cool, but the fact of the matter remains that aside from the hand-drawn elements, the design is very amateur. I do love the Diablo-esque art but at the same time it does little to push the boundaries of standard card design. Then again, that's not their intent.
Back to the amateur aspects, though; what irks me is that people think "if it looks cool, it IS cool" is appropriate for playing-card design when, in fact, that ideology is completely false in all other aspects of our lives. An entertaining movie may have huge errors that are laughably terrible. Millions of people have seen and loved Transformers, but that doesn't make its giant plot-holes forgivable. The writing in the movie, while entertaining, was in no way amazing and could have easily been written by a talented teenager. Nothing in that movie screams "the talent we have on our production is non-existent in any other production."
In a world where we have 10-20 new decks every month it really goes beyond "oh that looks cool!" The Trace decks look kind of cool to me, and if they were the only decks coming out this month I would have picked them up regardless of the fact that they take no talent to make. However, there are countless other decks coming out. If I find myself asking "Do I buy the Fantastique or the Infinity?" why on earth would I ask myself "Red Trace or Infinity?"
No matter how rich you are, money does become an issue at some point. For those who may only buy one or two decks this holiday season, they may look at the Vortex and skip out on it in favor of something that, in their eyes, is perfection. They will pick up the decks they know for a fact are everything they want, and are also what everyone else wants as well.
No matter ho much you guys say "just buy what you want and you'll never be let down!" that is never the case. People buy what they think will make them look awesome in a video or would be great to show off to their friends. Heck, it applies in all aspects of our lives. The clothes we buy are made to make us look good to someone else.
A critique judges standards in something. Art has standards. Any of you that have taken an art class or studied design on your own know basics like consistent typography, focal points, color balancing, etc. No matter how awesome a pink/green/yellow website may look to you, it will NEVER be rated positively by the standards to which we hold websites today.
So if you like the Blades, you like something that is, by any accepted modern standard of art, a mix of amateur design and great hand-drawn design. You can't work your way around that. Many would argue liking something outside of society's standards makes you unique and awesome.
Besides the cards are meant to be handled. Aside from the fact that soft stock simply does not last as long, they are amazing (in my initial review on UC I said it feels like they come pre-powdered).
I have personal issues with De'vo - but a product is a product and the cards I believe are not even designed by him. I also despise BBM for their tactics, but the designer of the cards? I have no reason to be "bias" against his work, which is why I kind of love the Samurai deck and the design of the Ryujins.
Heck, we all agree that Theory11's latest tactics of milking metallic ink is silly. Yet that has nothing to do with the quality of some of their decks. Likewise, the quality of some of their decks has nothing to do with how useless the "v2" Titaniums are.
tl;dr: A product is what it is. Bias has nothing to do with a good critique.