Not a fan of Mr Macaroon, but thats how diplomacy works. If you spit in someones face and call them names you are closing down avenues of discussion.
If you call putin a 'blood thirsty child killer' at the international level, russia will not talk to you. Because if they did by proxy they are acknowledging your previous statement - imminently putting them at weaker negotiating position.
Just imagine a situation, you have argument with someone - they keep stealing your cookies, you want them to stop - they spit in your face and call you dirty liar, would you keep talking to them or buy laxative cookies?