You're not about to address the analogy, are you?I'm sorry. I see no analogy.
Your hypothetical law prohibiting bah mitzvahs is a blatantly unconstitutional law against one particular religious ritual that is performed by members of one particular religion.
Marriage is a union between a man and a woman. The state confers certain rights and privileges on such a union. If you want those rights and privileges, find someone you can form such a union with and you will qualify for those rights and privileges. There is no requirement for people to get married. Many people live their entire lives and don't get married. You don't have a "right" to a marriage. If you wish to have a marriage, the rules and requirements are quite simple. If you don't want to follow those rules and requirements, don't get married. What's so hard about that?
An analogy to this would be if we had a law protecting Muslims and Catholics and other non-Jews that said that everyone is eligible for a bah mitzvah, and they don't have to observe any part of the Jewish faith to have a bah mitzvah and to get all the privileges and benefits that go with a bah mitzvah.
Willfully blind. Try pondering this phrase: Disparate impact.
A law against bar mitzvahs has a disparate impact against Jews since ostensibly they're the only ones wishing to participate in a bar mitzvah. Laws against gay marriage have a disparate impact against gays since ostensibly they're the only ones who would wish to enter a gay marriage.
Just FYI, I'm not in favor of gay marriage. But I'm not about to intransigently cling to ridiculous sophistry to make my case against it. I think there are better arguments than speciously (and flippantly in my opinion) offering that gays can simply marry someone of the opposite sex.
That does nothing to lend you credibility. It only makes you look like a domineering curmudgeon.