The Supremes here in Washington (the good one, not the one loaded with parasites) voided several constitutional-amendment initiatives too, on the same grounds - more than one topic.
In this case, I don't see much of a distinction in principle between civil union and marriage. It'll be interesting to see how this shakes out.
Liberal judges think voters are too stupid to know what they voted for. Dem liberals are much wiser than the stupid herd, which needs to put in their place and told to stop doing silly things like undoing judicially created gay marriages.