New Hampshire legalized same-sex civil unions on May 31, 2007, and it went into effect January 1, 2008. I didn’t notice any contemporaneous natural disasters...
Same-sex civil unions are not the same thing as marriage. Even homosexuals (and homo-friendly judges) consider civil unions inferior to true marriage. As for Massachusetts and Connecticut, which do have court-mandated same-sex marriage, perhaps they are seen as smaller than California, and thus not worth making an example of. After all, Sodom and Gomorrah could not have been the only two immoral places in the world at the time they were “zapped.”
There were Santa Ana winds long before homosexuals came out of the closet in California. However, the overbuilding in fire-prone areas of CA has gone on for decades. Remember "ET" from the early 1980's, and the giant subdivision under construction that the kids rode bicycles through? Multiply that by tens of thousands, and you start to see the problem.