Welcome to AT Novbert!
Thank you for this thread, it gave me ample food for thought.
I disagree with you in a few points, and below I give you my own ideas. While I think you are right in some aspects, I also think that you 'assume' many things, and relies heavily on psychology to explain tarot. While tarot and psychology may mingle, they are two distinctive animals, and I think that these boundaries should be respected.
To be honest I'm pretty new to tarot and these forums, yet I'm just surprised that many folks here actually use tarot cards for "telling the future", or to "get answers". Some even say that "the cards were wrong" and "they didn't predict the future correctly so they don't work". Of course there are others who say that cards are only tools and the reading is the reader herself.
Hum... why the surprise?
Tarot, and other divination tools much more ancient than it, have been used for centuries to foretell the future. The who 'psychologization' of the tarot and divination is something very recent. I read the cards for many reasons - one of them is to tell the future. And whenever that failed, I never blamed them, only myself. The cards are tool, and I would not use them if I didn't trust that they work. But I know I can fail.
Think about it: If you remove all the esoteric mumbo-jumbo from tarot reading, what remains? As I see, this is the case: The reader sees a random set of images in a predefined pattern and she tries to find a meaning for this random stimulus based on her assumpions, knowledge and impressions of those images and their position in the big picture. Unconsciously - or semi consciously - she projects her own biases, thoughts, fears and hopes into those images - basically that's what makes them relevant for her situation and understandable for her.
This phenomenon is known by psychologists for decades - it is used in projective tests like in Rorschach test and such. In those tests random and unstructured images are presented to the viewer and she is asked to find meaning in those images, to describe them. The theory is that the viewer will project the current state of her psyche onto those unstructured images, thus her response on the image tells more about herself than about the image.
What is exactly the esoteric mumbo-jumbo you talk about? Is that the symbolism of the cards? The simbology? The metaphorical imagery? The archetypes?
While there are a lot of esoteric mumbo-jumbo associated with all forms of divination, I think we have to be careful before stripping tarot naked and claiming "it's all psychology and projection". Sorry to say, but some symbolism was there when the formal psychological theories were wearing diappers. Of course... the unknown mind that created tarot cards as we know it, and all minds that helped to develop it, were human minds so there is indeed a lot of the human psyche in tarot. But I think that limiting tarot to psychology makes it poor.
Besides, the idea that you offer somehow implies that one would not need to study tarot in order to learn it. Since all associations are made inside the person, and what she sees in the cards is mainly what is inside of her, there would be no need to learn any of the tarot symbolism, or study its history. Each reader would come up with her meanings and structure, based on their own psychological responses.
And not only that - the person would not be able to read for others. How can you read for someone else if the cards are simply a mirror of your own psyche? Because all cards would be associated to your own inner world, you'd only be able to read yourself in them.
As I see tarot works very similarly. What you get in a spread is pretty much random - even if you're convinced that it's not.
I am not particularly religious, but I know a lot of people would would disagree with this idea of 'randomness'.
The only reason that you find a spread meaningful for yourself and your situation is because you project your situation onto those cards. (another person would probably interpret the very same set of cards in the very same spread totally differently - and you both would be right!) Of course believing that the cards aren't random, but relevant for the situation because of the <random esoteric expalantion> actually helps the process of projection because it makes the reader unaware of the fact that she's actually projecting.
I do not deny the whole idea of projecting, but for the reasons I stated above, I disagree that this is the explanation of how tarot works. The problem I see is trying to insert logical science in an area that is not particularly logic or scientific (at least not in the way we usually use these words).
The RITE method described in Mary K. Greer's book relies heavily on the querent's responses and I don't think anyone could read without such direct and immediate feedback. As I see online reading is an interesting game at its best - pure charlatanism at its worst.
On the other hand, considering all the aforementioned things, I still don't think tarot would be useless or not worthy to learn. It can be used for good and it can be even helpful and a fulfilling experience for both the reader and the querent. It's a great psychological tool, but thinking it's more that that is plain stupid - at least as much as thinking that it doesn't have anything to do with psychology.
Not everyone reads like Mary Greer does, although she is a fantastic reader and author and I very much respect her. That is the method she developed, and I do not think it's right for you assume that it is the only true method for tarot. Like you stated in the beginning of the thread, you are pretty new to tarot, so I believe you should research some more, and experiment with the cards in different ways before making any conclusions -- specially ones that blatantly call other practices 'stupid'.
Also, limiting tarot to a ' psychological tool' because it is the only way you can explain why it works, is like going to Louvre Museum to only see the Mona Lisa. While La Gioconda is really a masterpiece, you have thousand of other masterpieces equally beautiful there. She is simply the one that is more popular, and if you focus solely on her you'll miss all of them. Like the 'psychological' explanation for tarot - it is simply the explanation that suits those who cannot believe any anything out of the ordinary, and thus it is more acceptable.
However, you'll be missing a lot of the tarot's beauty and potential. You'll already begin your study of the tarot seeing everything through a tube, which is limiting. Of course it works too, but much of the interesting stuff is lost in the process.
Divination was here before the Projective Tachnique was around. Do they have a relation? Probably - both things were created by the human mind. But Tarot was not created be used as a projective tool, and it would be interesting if you could look into the other possible usages for it without judging them so harshly. They too are part of the tarot.