What is being denied is a legal status to that marriage. Since we choose to have our elected representatives define legal agreements or status such as marriage, adoption, corporations and LLC's etc. then we also give then the authority (unless we bypass that authority and make it a direct referendum) to decide just WHO is and WHO is not legally entitled.
Our Constitution is VERY specific as to what "rights" IT grants and what "rights" are to be determined by the people. Just because the people disagree with a certain proposal does not mean that it suddenly vests into a Constitutional Right.
We DONT always get what we want in this country, but when we attempt to change the Constitution to meet our agenda rather than the other way around we defeat the whole purpose of that document itself.
This is NOT to say that in hind site all of our laws have been just. But I, unlike some of you it seems, have far more confidence in the longterm fairness and judgement of my fellow citizen than I do some politically appointed jurist(s).
Personally I am not all that opposed to gay marriage laws and fully support gay union laws that give those unions the same legal protections as marriage laws. To be honest, if it came up for a vote here, Im not sure I'd feel strong enough to vote one way or the other.
What I am STRONGLY OPPOSED to is having some judge or cabal of judges deny me my right to self government by overturning my popular vote or the decision of my elected representatives based on their own self opinions of how THEY think the law should read.