Critiquers can give you a new perspective on your song, and your musicianship may even grow as new ideas will be presented to you. If you get a bad critique, this can also prepare you for dealing with rejection. Consider the advice that is presented to you, have enough modesty to accept the advice (if you agree with it) and move on. Don’t respond back to the critiquers telling them ‘they didn’t understand the piece. Your music just did not communicate it to them. You should never have to explain your music. It should speak on it’s own.