<If you don't like what the Catholic Church is about you are free to leave and find another church--where they teach, believe and practice the Faith you think they should.>
I suppose you think that's witty, or profound. or sensible ... but it's petty and comes out of a radically impoverished understanding of the church.  It seems to have the intention of ending a conversation, and in reality, it usually does.  
Erasmus of Rotterdam, responding to Martin Luther's question, "Why do you remain in the church?", is supposed to have replied, "I put up with this church in the hope that it will become better, just as it is constrained to put up with me in the hope that I will become better."  Works for me.