See: http://www.nauvoo.com/library/card-hypocrites.html for one of the reasons people find him repellent.
Choice quote (after he had a chance to reflect on the response to his essay):
"...it has become clearer and clearer to me, since writing this essay, that gay activism as a movement is no longer looking for civil rights, which by and large homosexuals already have. Rather they are seeking to enforce acceptance of their sexual liaisons as having equal validity with heterosexual marriages, to the point of having legal rights as spouses, the right to adopt children, and the right to insist that their behavior be taught to children in public schools as a completely acceptable "alternative lifestyle." It does not take a homophobe to recognize how destructive such a program will be in a society already reeling from the terrible consequences of "no-fault" divorce, social tolerance of extramarital promiscuity, and failing to protect our adolescents until they can channel their sexual passions in a socially productive way. Having already lost control of the car, we now find the gay activists screaming at us to speed up as we drive headlong toward the cliff."