Because Malicant and his cultists wanted Tu Vishan unconscious for a reason. Should he wake, then we may be able to find out much. And this is not even factoring in how beneficial his revival would be to the Kedan. If what I am told correctly, his rounds were a large part of their trade and diplomacy.

Going home is not much of a priority - time does not pass in our worlds, and most foreigners are only here for a few years at most.