title: Could someone explain the pros of deleting (or keeping) unused code?
body: <p>I have heard many times that unused code must be deleted from the project.
  However it is not clear for me "why?".</p>
  
  <p>My points for not deleting that are:</p>
  
  <ul>
  <li>Code is already written, and efforts are spent</li>
  <li>Code may be tested on syntetical and real environment</li>
  <li>If organized well (grouped, separate package, loosely coupled etc) it doesn't disturbs you on overall code analysis or refactoring</li>
  <li>Code may be used in future</li>
  <li>When deleted, author may feel uncomfortable</li>
  </ul>
  
  <p>Could someone explain the pros of deleting (or keeping) unused code?</p>