That's how it goes. You can't expect the US Congress to do the right thing. They pass the Fugitive Slave Act, the Defense of Marriage Act (signed by B. Clinton), laws against abortion, laws favoring banks and coal companies at the expense of the poor and workers, etc. Read Roe v. Wade. The court wanted to do something that Congress wouldn't but they had no justification for doing it, so they made one up. It's utterly contrived. Striking down DOMA was only slightly less contrived (and 5-4 instead of 7-2), and only because modern courts are getting so much better at contriving things due to all the practice.
But the same Court gave us Dred Scott and Buck v. Bell and Bush v. Gore. The same Office of the President gave us Hoover and Nixon and Bush Jr.
Gay couples are only happy today because Justice Kennedy is the swing vote, but Kennedy was appointed by Reagan. If Reagan appointed somebody else then DOMA is upheld and any state can ban same sex marriage. So we have a federal government that will pass DOMA with a large bipartisan super-majority but strike it down by the narrowest of margins, when we could have one that much more clearly has no authority to be involved in the matter at all.
Countries need a strong central government to overrule local governments ruled by prejudice. To think otherwise is historically illiterate.
Changing the size of government doesn't fix any problem created by majoritarianism. A larger government only makes it so that when the majority gets it wrong, they get it wrong everywhere at once and there is nowhere left to run.