I think that, like anything else, the amount of care and knowledge that goes into a deck is obvious, and it goes for changing things around, as well. It also matters if you can justify your choices in a way that will be accessible to other people.
We've all seen decks with bad artwork that are also conceptually poorly thought out. In these cases the deck's creator may as well just say that they changed suit names because they thought it would be cool or interesting. This category may also include "art" decks that serve to show the artist's skill and imagination. This isn't bad exactly, at least not in and of itself, but does serve a very specific purpose which perhaps isn't strictly Tarot-related.
On the other hand, there are decks that are truly unified in concept, where every element is well thought out both in internal consistency and in relation to all the other elements in the deck. In these cases, changes are truly steps forward in the development of ideas, and can be very exciting to contemplate. These kinds of decks usually have reams of informed justifications for any changes made. Even if you don't agree with these changes, you can at least accept that a valid point has been made.
So I wouldn't say that any changes in suit names necessarily means the artist had no knowledge of Tarot, but I do like to see some thought behind the work being done. It needn't say anything about the artwork but with the cohesion of the idea the deck is trying to put forth.
So basically, if you're putting orbs instead of coins (while keeping them Earth), that's great, I just want to know why. If it's just because orbs is more New Age-y, that's kind of a dull reason, and chances are a deck like that won't interest me.
Lastly, not all decks are on the same level, and this has nothing to do with how good they are or how good the readings they give are. It's like the difference between "The Little Engine that Could" and "War and Peace." "The Little Engine that Could" is a great story, really it is. It's touching, it teaches an important moral, it's written well and has excellent pacing. But as good as it is, it simply isn't Tolstoy, and will never be. It doesn't have the complexity, breadth or grandeur of War and Peace. I love bang-bang action flicks, but atthesame time I can recognize the Citizen Kane is "quality," although I enjoy both genres. Same with Tarot decks. Something like the Halloween deck is meant to be fun and enjoyable. Whether one's readings with it are deep or not, that still doesn't change the fact that it isn't made of the same stuff as the Thoth or Hermetic. In the case of the Halloween Tarot, fun, "pop" changes are funny, cool and self-aware of what the deck is, and its nice to see something not take itself seriously. Some decks are "just" nice, and that's fine, and changes are fine and welcome and good. In this case, give me leaves, orbs, bats, jewels or whatever, it doesn't matter.