Definition is not endorsement

A website called GayStarNews has cheered the news that "the world’s most renowned dictionary of the English language has officially changed the definition of ‘marriage’ to include gay people."
They mean the Oxford English Dictionary. News may not yet have reached them that Merriam-Webster's Unabridged also has "(1) :  the state of being united to a person of the opposite sex as husband or wife (2) :  the state of being united to a person of the same sex in a relationship like that of a traditional marriage." 
What bothers me is not that same-sex couples have been grated the benefits of civil marriage, or that the phenomenon has been recorded in dictionaries, but that word officially. It speaks to me of confusion about the nature of authority. 
Lexicographers strive to be authoritative. That is, they ransack speech and text for all the senses of words they can find, trying to pin them down as precisely as a lepidopterist distinguishes among species, subspecies and varieties of butterflies. But that it the only authority they claim, and it is a mistake to ascribe the other kind to them. 
The other kind is the official, the legitimizing, the endorsing. Same-sex marriage is a thing, a noun, a word labeling a phenomenon that occurs in numerous states and nations. Once there is a word for a thing, it is the duty of the lexicographer to record and define it. But that is as far as it goes. Dictionaries include polygyny and Nazism, too, but you should not take that as a recommendation of either. 
"It's in the dictionary" is an attitude that asks the word-hoard to carry a heavier load than it is built to sustain. Advocates of same-sex marriage cheer, "We're in the dictionary! We have arrived!" Opponents of same-sex marriage shudder, "That awful thing has insinuated itself into the dictionary!" Both exaggerate the significance. 
The same thing happens when the hard-shell prescriptivists, the peeververein, bemoan the corruption of the language when some word or sense they dislike becomes widespread enough to merit definition. Kory Stamper encourages them at harmless drudgery to cool their jets
Lexicographers are merely trying to record a portion of the world as it exists. That's the one to live in, don't you think?