I know I stand a good chance of being ridiculed for this, so please hear me out, but feel free to ignore this issue entirely.
Hints are sometimes phrased as "Perhaps you should remove it." which seems to imply that "a person who does remove it is a better person".
  
  
    
        
          |  | f msg (Just x) | null xs = [msg ++ " you should remove it."] | 
    
   
 
This issue exists just to suggest replacing "should" by "could".
Or even: "You may be able to remove it."