The logic of the decision is pretty simple - civil marriage is just that - CIVIL marriage. At that level, they are carrying out a service as agents of the government, not as agents of their particular faith community. As agents of the government, marriage commissioners are obliged to treat all citizens equally.
Predictably, Canada's right wingnut religionists have begun complaining:
“What we are seeing now is that step by step religious rights in Canada have been diminished while homosexual rights have been accelerated by the appointed unaccountable judges,” Landolt told LifeSiteNews.com. “This decision means that religious rights have been pushed to the side once again in favour of judge-made homosexual rights. If there were genuine equality between these two competing rights, then both should have equal recognition under the law which has been denied by this decision.”
“Canada has suffered a severe loss to its collective rights and identity today,” said Christian Legal Fellowship (CLF) Executive Director and General Legal Counsel Ruth Ross, in a press release.
Where, might I ask, is there any "restriction" being laid upon what an individual believes? I don't see anyone saying that an individual must like the idea of a same-sex marriage. Rather, what we see is that where government functions are concerned, they must be carried out on behalf of all citizens equally.