Because guess what, in our society you can’t live without it! Yes, gay people want to be able to put they one they love on their health insurance so that if something bad happens they can get treatment. Gay people want to leave their partners their pension benefits, because they worked as a team throughout life. They want ownership of their house to default to their partner, instead of to the bank or another relative. (Even if you will something to someone that you’re not married to your kids or other relatives can challenge that in court saying it was rightfully theirs.)
So yes, a lot of it comes down to money, but it’s hardly mercenary. If your husband is a good man he wants you to be protected in all of those financial ways as well.
I am sorry, but house transfer and other property transfers at death are easily taken care of. You either buy the house together, (It is called joint tenancy with right of survivorship, and can also be done on things like cars, and bank accounts, and this allows the property to transfer automatically), or you make a will. (really not that hard).
I don’t know if I have ever heard of a house defaulting to the bank, it would go to the state first, (I guess if it still had a underwater mortgage the state might just let the bank foreclose it).
The real lesson here, is if you don’t like the default rules (intestacy statutes) then make a will or plan accordingly.
It is easy to gain access to a person in the hospital, it is called a medical directive or a power of attorney.
Almost all of this stuff is achievable with the right planning.

If you are really that committed, buy a house together and get both names put on the deed. Or make a will. The only things that aren’t a given are social security benefits. Even most pension benefits are given to any named beneficiary (people who get divorced often run into this problem as they forget to change the beneficiary and then the ex gets the pension, much to the ire of kids or new spouse.
Even regular couples should do this, you can’t assume the intestate laws or other default rules are going to be what you want to do. There are only a few things you can’t do and that is disinherit a spouse or a minor child. (Up to a certain amount). The reason these laws were enacted was to protect children/orphans and women who had been at home with the children or just because women couldn’t get jobs. This really isn’t the case with homosexual couples. (I would advise any homosexual couple to maintain separate back accounts where their paychecks go and potentially a joint, where they would transfer limited amounts of money for household expenses).