Partly because it's impossible, given the paucity of information. Partly because it's an irrational approach to take when no two people will come up with the same assumptions, let alone the same application of those assumptions. But mainly because it's pointless: we already know where some key locations are, such as Jerusalem and the Sea of Galilee.
It's the same with the Book of Mormon. The information given in the text is too vague to support a coherent abstract map. It's anyone's guess how far one city is from another, for example, or even how far a Nephite would travel in a day.
But we do know the location of at least one key location: Cumorah.
This is also the sole location unequivocally common to both the Jaredite and Nephite civilizations.
How about if we at least reach a consensus on that location?
We can start by re-reading Oliver Cowdery's Letter VII.
I realize many people insist Cowdery was speculating and was wrong, but the only reason they take that position is because of their belief that the Book of Mormon took place in Central America. Isn't it obvious that this approach is putting theory before fact?
Cowdery said it was a fact that the final battles of the Jaredites and the Nephites were at Cumorah in New York. Joseph Smith concurred. He had his scribes copy Letter VII into his own journal and had it reprinted at least twice during his lifetime. No early Church author questioned Cumorah in New York.
These are simple facts. If we can't reach consensus on these facts, there is little hope of reaching a consensus on anything else.
In fact, in my opinion, if we can't reach a consensus on the validity of what Oliver Cowdery and Joseph Smith had to say about Cumorah, there's no point trying to reach consensus on any other aspect of Book of Mormon geography. Those who reject Cowdery's Letter VII reject him as a credible witness. They are rejecting the man who wrote the text as it came from Joseph's dictation, who received revelations with Joseph, who was present with Joseph for the ministrations of John the Baptist, Peter, James, and John, Moroni, Moses, Elias, Elijah, and the Lord Himself.
When I explain to people that so many LDS scholars reject Cowdery's teaching about Cumorah purely because of their insistence on a geography set in Mesoamerica, they don't believe me--until I refer them to fairmormon.org, the Interpreter, and the Maxwell Institute so they can see for themselves.
When you read those sources, you'll find all kinds of debate about which river in Mesoamerica was the Sidon, which of a dozen locations was Zarahemla, etc. It turns out, when you read the material published by those sources, that the only actual consensus they've reached on the topic is that Joseph and Oliver were wrong about Cumorah.
It's astonishing that the one point every LDS should agree on--that Cumorah is in New York--is the one point about which the LDS scholars have reached consensus. Except their consensus is that Cumorah is not in New York!
Letter VII is widely available online. Here is a link to the relevant passages in Joseph Smith's own journal: http://josephsmithpapers.org/paperSummary/history-1834-1836?p=90&highlight=camorah#!/paperSummary/history-1834-1836&p=89
A short commentary with additional resources is available here.