I don't think anyone is going to use these for their poker games, even if they were bordered, maybe once or twice for the novelty of it, but I doubt anyone would make this their regular weekly poker deck, so I don't know if it is worth changing something that really makes the deck look good, and since this is hot on the heels of two other decks of the same theme I think it might not be a bad idea to have this dramatic difference, even if it will lose the designer some backers.. Well, several maybe... I'm hoping it will hold on it's merit as an art deck.
And I would argue that if someone made a cheese platter with 52 varieties of cheeses, even if they were all 'mouldy' types of cheeses, that people would love it, the small cross section of card collectors that also love variety cheese platters would be pretty happy.
But I see your point. My vote is for image into the bleed
It makes for a pretty stack of cards, to be sure - just not a deck of PLAYING cards. Even most art decks I see have either borders or identical patterns from card to card at the die line. It's one thing if you have a deck that's got an all-black back and white backgrounds for the faces - people might complain that you can't use them for certain magic tricks, to which I say, "Big freakin' deal - magicians don't usually use heavily-custom decks and there's a zillion different decks better suited for magic anyway. The one time it became an issue worth fussing over was when a magic company (Ellusionist) did just that for what was to be a flagship deck line (Artifice) - it was a case of a deck for magicians with a serious flaw for use by magicians.
There's not one good reason, other than cheating at cards, for having a design that allows one to identify cards in a deck by looking at the deck's edge. Unless, of course, as I pointed out in the first sentence of this post, you're making cards, but not PLAYING cards. Lots of people make cards every day that aren't playing cards. Some make cards that look like playing cards, but they really can't be used in fair play, so they're not what one could consider playing cards - this would be in that category. A magician could have some fun with them as a marked deck, perhaps, but for a card game, nope - I'd never use them.
In the end, it's up to what the artist a) wants to create and b) knows he can sell. Having a) without b) is a formula for financial failure (or at the least, a non-starter on Kickstarter), having b) without a) is a formula for the artist's dissatisfaction - gotta have both.