Something is wrong with this reasoning!?

i don't understand why it is possible for serial killers, rapist, child molesters, and wife beaters to get married while they are incarcerated, but it is not ok for 2 gay people who are good citizens, tax payers, and contributors to society to marry and live a happy life. if you are going to ban gay people from marrying then you also need to make it a law that these serial killers, rapist, child molesters, and wife beaters can not get married and have conjugal visits in prison. this is the main reason why people are upset. i am not gay/biual and i don't believe that it is natural, but i also don't feel that it is my business who these decent people fall in love with. i am only concerned with my own partner. and the military issue is just ridiculous. they are risking their life and defending this country while people who are too afraid to fight deny their right to live their private life. what are your views on this.