I think that "Question list" and "Responses" at the same menu is highly illogical.
I fear you will find more illogical things in Limesurvey. This software has been organically growing and each new team member has included features and names and this was not always strategically supervised.
However, I fired up my LS 4.x and could not find "Question list" and "Responses" in the same menu:
"Question list" can be found in the left bottom menu block while "Responses" can be found in the top menu within the right block.
Overall, I agree that the menu structure is surely not ideal. I think when the new interface was designed the opportunity was lost to have a more sistematic approach to make sure the navigation is logic and user friendly. From what I remember there was very little discussion with the community, but it was rather the work of one developer.
I was one of the first ones asking for a more modern user interface, but turns out the layered approach from 2.06 and before was way more logical and straight forward in retrospective, because I don't think that the proper time was given to design a logical and easy aproach for the navigation with a modern design. Now we don't have a specifically logical and easy to use navigation, nor a specifically modern design.
But before we think about approaching any of this, I think LS 4.x needs to get on the right track to become stable. From there we can work towards more usability, if this is something the developers are interested in.