I believe the Lenormand is popular because there is a system, with meanings to be used, and it's very definite. This is part of what appeals to me, and why I have become interested in Lenormands. However.....
I'm going to go out on a limb, and propose a possible idea some friends and I were batting around earlier...
To many tarot can seem vague. This is perhaps because there IS a wealth of information to be gained from each card, and once you gain a general sense of what each card stands for (Assuming you decide to have a good knowledge base to work from instead of going with the 'just wing it' philosophy) you then have to decide JUST how it applies, in its many permutations! This is done using intuition (which I believe would apply to some degree in Lenormands, too, but I'm not entirely sure -- I just want to learn Lenormands, but haven't had time due to my college workload)
This is where people can falter..afraid to offend, or even just to trust their own intuition, they give a very general idea of what the card may be about. Instead, they should understand they're learning, and take that leap into the unknown! You can't learn without making mistakes.
Also important are spread positions -- another thing which is popular to ignore! However, if you DO have positions, it acts as a combination to the card occupying it. For instance, for a daily spread you have Works, and get the 5 Swords. This could mean, you'll have a run in at work with coworkers, be aware of this so you can handle it correctly! Or perhaps in the "Influences" position there will be a card that, to you, indicates your boss. You'd want to handle that far differently of course!
Of course, if that were in the self position, you wouldn't feel warned about that, instead you may decide an internal battle with your own feelings appears, from morals, beliefs, rights, or religious path -- you'd gain information on that from other cards, and intuition.
In short, I think tarot is vague because people like to play it safe
But there is a system, albeit MUCH more complicated than in Lenormands (78 cards vs. 36) It is there to be learned, if you wish. Of course, you WILL need intuition as well -- but I haven't heard of a Lenormand reader that doesn't use that as well
(This is where the non-intuitive readers will crawl out of the woodwork and say, HAH! ROFL)
So, I'm interested in Lenormands because there is a system to base it from. I'm also interested in playing card divination, for the same reason. (that and playing cards have been a part of my life since I could hold a deck.) But, my interest in tarot will continue -- for the same reason!
However, I have absolutely no interest in 'standard' oracles that prompt you to just wing it...
~Yira