QUOTE: "Why should we expect either The Bible or Revelations to provide a complete "explanation"?"
I think the question is, if the Bible or Revelation is assumed to be the source of the tarot, then why would other images be included which do not seem to be relevant or explained within that context? If we do not assume that there is one 'all-encompassing' explanation of the tarot, then we open the door to many other partial theories that leave some images uncovered.
It's like putting a puzzle together. If we start building a puzzle, and then notice that some of the pieces are missing, we might still get a pretty good idea of what the whole picture is supposed to look like. However, if we're working on a puzzle and notice that we have some pieces that don't seem to fit, then we either have to discard them or force them into place somewhere. In this case, we might ask ourselves why the puzzle-maker put them in the box in the first place.
QUOTE: "Can you tell us why it is "not that clear" as to whether those images were meant to have the same meanings as they may have been associated with in the Bible?"
In the Middle Ages, artists were limited to using traditional material (which was mostly religious/biblical), and were not yet in the mode of creating for personal expression. Therefore, any attempt to create a new form of expression like the tarot cards would also be bound to using those same traditional images. However, if we are to assume that all of the images must have kept their original meanings, then we shoud also conclude that the biblical references of some of the cards like The Emperor, The Empress and The Chariot, for example, would have to yield to their sources in Greek Mythology. As history progressed, and culture changed, artists used the same images to represent new and current meaning. So, like the Emperor, whose image was sometimes used to refer to Jupiter, we might infer that it could also refer to a more current emperor of the time, like Frederick II.
QUOTE: "And again given the popularity of tarocchi cards, can you imagine some reason why, if the images were NOT intended to be read as Bible images, that some proposed new, alternative interpretation did not become known as a popular standard interpretation among users? Or how, if the "true alternate" meaning was intended for only a certain sympathetic portion of the audience, it would have been kept under wraps from the rest of the masses?"
It is very possible that the tarot was used for more than one purpose. It seem to be clear that many people used it simply as a game of cards. In fact, this was probably the 'main' use of the tarot. If, however, some smaller group of people figured out an alternative use for the cards, this may have been subjugated through history simply by the sheer numbers of poeple involved. In other words, the greatest use for the cards is the most likely one which survived and became the standard. The reason for an alternative use not becoming widely known may have to do with its intention. For example, if the cards were used to conceal messages not approved by the Catholic Church, then there would not be a rush to get that out to the general public for fear of reprisals.
At this point, we might ask, why would we even consider an alternative theory of the tarot? To me, the answer lies in some of the questions that can also be asked:
1) Why do some of the cards, like the Popess, seem to have heretical themes?
2) Why were some of the images on the cards changed from the Italian decks when the tarot was brought to France? Why was The Fool's image, for example so drastically altered?
3) How can we explain some of the images used, like the dogs and the crustacian on The Moon? It would seem suspect to asign these to the randoom or arbitrary expressions of the artist's imagination.
So, I believe that we should be looking for an explanation that handles all of the above questions and wholes, and not just some. In this way, we can possibly arrive at a better impression of what the puzzle should look like.
Of course, is it possible that the imgages used in the cards don't necessarily have any real cohesiveness represented by a single theme? Sure. But then I would ask myself why someone would bother to put those cards together in that way.