Because Sir Ian is as gay as they come and that's why he tears pages out of Leviticus.
McKellen, an admitted homosexual, later explained that the theater introduced him to other gay men, which eased his acceptance of his own sexuality. He became a vocal activist, and one of a handful of openly gay knights when he was knighted by Queen Elizabeth in 1989.
In 1993, he became recognizable to American television audiences playing gay men in And the Band Played On and Armistead Maupin's Tales of the City, two acclaimed TV miniseries; McKellen earned an Emmy nomination for his work in the former.
http://tribute.ca/bio.asp?id=2373
This may be a fact you already know, so I apologize in advance if you are already aware of his homosexuality. I imagine Sir Ian really hates Leviticus since that's the book where there is some VERY strong condemnation of homosexuality.
I don't think Sir Ian (who once told a crowd "but you can call me Serena!") is exactly closeted, no. Heh.
I think he's a wonderfully gifted actor and do not begrudge him his stance on political or, certainly, religious matters. But I don't like the ripping of other people's property, and his misbegotten comments at what's supposed to be an interview to GET FOLKS TO PAY TO SEE THE MOVIE. Even the most liberal of Hollywood producers would be irritated at him saying this "fiction" stuff THEN and THERE.
Since Jesus saved us, those old Testament sins are no longer applicable.