It's thousands of miles that way-->
Also, people are still getting to know Tamriel. Elswyr, Valenwood, and Blackmarsh also have a very large room for lore expansion as well as plot development. Why drive to Canada to examine the forest when you can do so in your own backyard. (Please substitute a different country if you are, in fact, from Canada, or in a country in which one cannot drive to Canada.)
Then again you can examine Canadian when you see one in you hometown. Just as wise men of Tamriel could study Akaviri races. It's well known fact that Tsaesci blood flows in considerable section of Imperial (noble) families still. To me lore gives impression that Tsaesci-population during 2nd era was considerable, cross marrying between Tsaesci and humans was considerable. Tsaesci as a race shouldn't be that mysterious. Even when humans themselves weren't and aren't very happy about common era and how they were led by Tsaesci.
Legions even invaded parts of Akavir, they remained there for some time quite surely there was someone enough interested to take notes. Little is known outside invasion's progress, outcome and costs. Well maybe Mysterious Akaviri is seed of that invasion?