Maps of imaginary lands, as found illustrating the frontispieces of fantasy books since long before Tolkien, are usually so bad the only thing they chart is the ignorance and idiocy of the authors. As Alex Acks puts it, in the first a list of ten objections:
...terrible. Like geographically, geologically terrible. You’ve already probably seen me complain about the map of Middle Earth. From my experience as a reader, and I’ll readily admit that I have neither had the patience nor time to read every fantasy book ever written, the majority of fantasy maps make me want to tear my hair out as a geologist. Many of them are worse than the Tolkien map, and without his fig leaf of mythology to justify it. (And sorry, it’s not a fig leaf that works for me.)
Allow Paul Weimer to retort:
It might be facile to hashtag #notallmaps, but, really, not every map is a geologic mess,not every map is a Eurocentric western ocean oriented map, with an eastern blend into problematic oriental racial types. Not every map has borders which strictly follow natural barriers and does not have the messy irregularity that real world maps and borders have.
This is a hot issue right now because (its other virtues notwithstanding) Game of Thrones has such a terrible map it could be presented as a parody of bad fantasy maps.