Coincidentally, I'm reading a book that offers an interesting insight on this point, and I wanted to share.

Most conservative Christians and Mormons, while recognizing the Greeks' artistic and social and political achievements, would probably not choose for their own homes any replicas of such statues. I even heard of one LDS stake president who called Michelangelo's David "pornography." My parents once attended an art festival and purchased an original sculpture, small enough for a tabletop, of a man & woman passionately embracing. Both were unclothed. They put it in the living room. I thought it was beautiful and very tasteful. But apparently somebody from church saw it during a visit and complained to my parents, so they moved it to their bedroom. Apart from the gall of criticizing someone's own choice of art in their own home, I was amazed at the aggressive prudishness. How cleverly diabolical, to persuade someone that the mere sight of God's greatest creation is morally wrong (spare me the "sacred, not secret" bit, that's not the topic here). I understand my parents moving the statue because they didn't want to give offense to any other visitors. To my dad's credit, it's now back in the living room.
Art like that, no matter how tasteful, makes a great many conservative Christians and Mormons uncomfortable. They're baffled by why the Greeks created so many unclothed statues. Their religious tradition's heavy overlay of original sin and the idea that the flesh is corrupt, plus the hysteria that has overtaken modern American society about child molesters and sexual abuse and wardrobe malfunctions in Superbowl broadcasts, all seem to have robbed almost all American Mormons and Christians of any ability to think calmly and rationally about anything less than fully clothed in a way Queen Victoria would have approved. But this book I'm reading gives some compelling insight about why the Greeks created those statues, and why such art resonates with gay guys particularly. And I think also answers the MoHo question about appreciating depictions of male beauty.
Many straight people assume that gay people's attraction to those of their own gender is merely "abnormal" and "unnatural" lust, thus any appreciation of the physical form of someone of one's own gender must also be "abnormal" and "unnatural." Apart from the fact that this is just plain wrong, it is also demeaning and dehumanizing.
In fact, there is another aspect, much loftier, that's perfectly captured by the Greek statues and any art that follows the same lines, as so well put by the author of Sailing The Wine-dark Sea. It is that those statues capture an ideal:

The kouros, then, is not merely the expression of a Greek idea but of a profound human longing that the Greeks were the first to uncover and that reverberates through art and literature ever after . . . the wish to be absolved . . . from the "change and decay in all around I see"--and its expression in notes high and low, in measures quick and slow--whether in Homer's lost utopias of Troy and Ithaca or in Sappho's plangently expressed desire for youth and regret over age, whether in Socrates' earnest aspiration to "shuffle off this mortal coil" and ascend to the World of the Forms or in the molded pathos of the kouros--is Greece's most complex and valuable gift to the Western tradition. . . . The kouros . . . speaks with one authoritative voice: "Here is our ideal, the best we have to offer."

Gay guys get this; it's intuitive. But you don't need to be gay to understand it. I am sincerely sad for anyone who can't see this perspective, who may be so bound down by the traditions of their gymnophobic fathers that they can't comprehend this reverence and appreciation but remain stuck in the attitude that all such depictions are necessarily base and obscene. In fact it is that attitude which dishonors both the Creator and His creation.
Mormons are fond of the truism "As a man thinketh, so is he." So to anyone, Mormon or otherwise, who thinks these statutes or the "David" or anything like them are porn and obscene, I say get your minds out of the gutter and show more respect not only for others but for the Creator's work. Thomas Cahill, author of Sailing the Wine-dark Sea, is right; such art captures a way of thinking that honors divinity, invites us to aspire and achieve, and fills our lives with beauty. It's not porn, it's perfection. It's not shameful, it's sacred. It's not degrading, it's a celebration of the divine gifts of life and creation.