Why is it so bad to get the top of your ear pierced with a gun?

Its not bad to get your ear pierced with a gun, all my mates have got it done and some adults i know have got it done and they have had it done since they wer young and they got it done with a gun and there is nothing wrong with it! In most countries the use of piercing guns for anything other than ear lobes is a direct violation of health regulations. Piercing guns are not designed nor intended to pierce the cartilage because due to the manner in which the piercing stud tears the skin and punctures the cartilage it doesn't allow room for the skin to heal around the punctured cartilage, leaving the cartilage available for infiltration by bacteria and infection.