There is nothing Turbine can do to fix the forum search. Turbine didn't write it. The forum search is something that the company that sells vBulletin created, The only choices Turbine has are:
1) Pay many dollars to have the search feature improved by the owner.
2) Buy a different forum software product - Pay Turbine employees to customize the new package.
3) Pay Turbine employees to redirect all forums searches to Google.
4) Pay Turbine employees to disable the built in forum search capability. No longer a feature. No more complaints.
Turbine probably feels that there is no need to do anything. People will fire up another browser window. Use Google or some other search engine.
Unless stated otherwise, all content in this post is My Personal Opinion.