The vast majority of rights that are bound to marriage in the us have nothing whatsoever to do with "the bedroom" but rather practical matters like visiting your chosen spouse in the hospital or not having your non-citizen spouse deported or receiving benefits if your spouse is killed while serving in the military. Another good example is the right to file taxes jointly which can have a huge impact on your joint income. Many of these things couldn't be covered by contract and even when they can technically be covered like allowing someone to make end of life decisions for you it costs money which opposite sex couples dont have to pay and contracts are frequently ignored by people like hospital staff who don't understand the law. When your partner is in the hospital suffering you shouldn't be stuck debating contract law with its staff and a single status, legal marriage, makes it crystal clear to all. While I do wish there was a code deprecation review committee in congress to eliminate things like financially favoring married couples at tax time practically speaking legally recognizing same sex marriage gets us much closer to equal treatment under the law much faster than debating each of those 1000+ rights individually. People in unrecognized same sex marriages are being actively harmed by their exclusion right now so IMO sitting around debating the perfect solution instead of moving forward pragmatically is harmful behavior.