It's just too wrapped up in the rest of the EU. If you greenlight Revan, you greenlight The Old Republic, and that means KOTOR, and then SWTOR, and then all of a sudden people are asking why the Emperor's Palace isn't on Dromund Kaas, and...etc. etc. etc. It's a snowball effect from an IP perspective.
It's a swamp planet that was turned into the Sith Empire capital but it has been abandoned for thousands of years. By this point it's just a swamp planet again, like Dagobah. If you were Palpatine would you rather live there or in a palace on Coruscant?