While I agree with you, it's worse than that. It is a law in an arena in which the goobermint has no business whatsover. For that reason it should definitely be removed. Your reasons are additive, but this one is fundamental.
Do you think people should be able to smoke pot in the privacy of their own home?
Yup. Snort Drano too if they wish.
§ 21.06. Homosexual Conduct
(a) A person commits an offense if he engages in deviate sexual intercourse with another individual of the same sex.(b) An offense under this section is a Class C misdemeanor.