To my mind, the "Search" box at the top of the page is poorly named. It isn't very useful for searching and is very useful for jumping to a specific node for which you know the title or the node ID or even just much of the title. I've long felt that the "Search" button should be renamed "Find". If you want to search, even with a single keyword, you are better off using Super Search or the google alternative it links to.
Anyway, this is why the "fix" you propose hasn't happened. It would solve a problem with the misuse of the mis-named Search feature while simultaneously breaking one of the most important features of the site.
Update: But doing just that isn't a very appealing "solution" either. How about s/Search/Goto/ and add another top-line input box for "Search" that actually uses Super Search to search node contents easily. Perhaps also move the links to Super Search into the top bar instead of with all the links just under it?