Wouldn't that mostly matter if you're really navigating in your source code via the tree panel? In the post-Textmate days, fuzzy file finders seem to be all the rage whether you're using vim or IDEs (or Sublime etc.). Or you go to definition/references immediately.

I mostly use the file navigation when exploring the structure, which I'm not doing that often.

And which I probably should do with a class browser anyways, which I used to do often in Eclipse, way back in time, but it seems that particular SmallTalk-ism isn't very popular in contemporary IDEs.