Because sexual orientation does not apply to age, only sex. That is how it is defined in English. "if a group can campaign for their sexual rights (LGBT), based on the idea that it is a sexual orientation, then what's to stop pedophile groups campaigning for their sexual rights." You are conflating LGBT rights with pedophile rights by suggesting that pedophiles could use the same justification that LGBT groups do. And there are a lot of people who think "niggardly" is a racial slur. They can think that all they like. It's not, even if it sounds like one (and even if people want it to be one for political reasons.) Why shouldn't pedophiles be able to exercise their Third Amendment rights to sleep with children?