Gays could always marry in this country. After this ruling, however, people were forced to recognize those marriages, regardless of their religious conscience. The matter has always been about frustrating people’s rights, not defending them.
The issue is really about all the ancillary benefits that accrue to a legally recognized "marriage". In particular, the ability to claim a spouse on employer sponsored health care insurance. That was a big deal to gays facing financial ruination from an AIDS infection. The individual liability for that behavior and costly medical consequences has been laid as a burden on employer sponsored healthcare insurance. Anyone paying healthcare premiums can compare the costs before and after this decision.