Not sure what the laws are in Britain, but here in the U.S. freedom of speech says you can say whatever you like, without fear of reprisal from the government, as any free society should be.(within reason..you cant falsly yell "fire!" In a crowded room, for example) So a person should be able to say whatever they wish. Now that doesn't mean they are free from all reprisal, such as a lawsuit for slander, or a swift punch to the nose.
Name calling is the hallmark of someone who's argument has lost all reason. Basically, if you resort to name calling, you're a punk ass bitch 😉. That said, people need to grow a thicker skin. Sticks and stones...