I'm not certain what the rules are for other countries, but the new conservtive government is trying to tackle child porn and gay marriage as per election promises. I presume the age question is an attempt to stop internet predators from getting their jollies. The gay marriage issue was resolved by the late liberal government, which made same-sex marriage legal countrywide. There were exceptions written into the law, e.g. religious groups [churches and such like] were not required to perform marriages whcih violated their morality, but the law was widely accepted as a "good thing". The key to the whole question was the universality of rights. If you could get married then so can I.
