What I don't understand about the gay marriage case

I should preface this by saying that I don't feel that strongly about gay marriage.  But I do feel strongly in favor of democracy and allowing votes to stand and I don't understand the basic framework of the gay marriage legal debate as it was argued in Perry v. Schwarzenegger before Judge Vaughn Walker.  Well, I understand it -- I am a lawyer -- but I don't understand why the pro-prop 8 people bought into the legal framework.

As I see it, the issue should not be whether marriage should be considered a fundamental right or whether states have a rational basis to infringe that right.  The case should never even reach that issue.  The first issue for me is whether a right is being infringed at all.  I don't see how gay people have a different right than straight people.  Rights are held by individuals and as far as I can tell everyone has the same right to marry which is now and always has been severely restricted.  Every unmarried person over 17 years of age has the right to enter into a legal state of matrimony with another person if that person is:
- Human
- Of the opposite sex
- Unmarried
- Over 17
- Not a close relative
- Not taking part in a sham marriage for immigration purposes
- Present for a ceremony
- Medically compatible and
- Willing to marry them

Everyone has the same right, gay or straight.  Love has nothing to do with it legally.  No one has ever had the right to "marry whomever they love."  Moreover, no one asks whether you are gay when you get married.  All gay people have the right described above.

So if everyone has the same right how is it that gay people are being discriminated against because they're gay?  How are they being discriminated against at all?

If people want to create a new right to marry people of the same sex, that could be done in the legislature which is the branch of government designed to make the tough ethical calls.  But that has not been done.

So what I don't understand is why the defense team at trial accepted the framework of the plaintiffs and argued about whether there was or was not a rational basis for infringing on the rights of gays.  Why even concede that any right has been infringed?

Putting that aside and addressing the reasoning the court did conduct, one thing seems quite clear which is that society has a "rational basis" for constructing marriage the way it has.  The reason society has marriage and preserves it for people of the opposite sex is to celebrate the kind of relationship that society has traditionally been built on -- an often tough relationship that is worth celebrating.  It's done a lot for us, so we want to celebrate it.  That is its rational basis just as the rational basis of Columbus Day is to celebrate the achievements of Columbus, the celebration of which is neither irrational nor intended to discriminate against people who prefer Ponce de Leon.