So what's to love?
Basically, Foucault is an historian of ideas. This means that his method is not evaluative; he's trying to examine and describe the ways in which ideas were formed, the concerns that drove people to formulate different philosophical problems, and the complex interplay between concepts and practices. I can see why readers who are fundamentally unsympathetic to sexual morality would come away from this book feeling that it's all just a matter of cultural powers suppressing the natural sexual good of human beings, but that's because they have certain premises which Foucault does not seem to share, and which, at times, he explicitly denies. The premise, for example, that because an idea develops within the social sphere and is promulgated throughout the populus by various means, some of them coercive, some of them persuasive, that the idea is therefore an impingement on individual liberty. Basically this involves doing something that Foucault himself seems opposed to: namely, attempting to take a thoroughly modernist framework for understanding the past, and using it to judge the way that people thought historically. Foucault explicitly states that this is not his intention, that in fact he perceives one of the primary goods of philosophy to be the fact that it makes it possible to get outside of one's own sphere of reference, and to have a deep, ultimately sympathetic understanding of ways that people think and have thought in other cultural contexts.
Hence my excitement about this book, which deals with the development of notions of sexual morality from ancient Greece through to the early Christian period. So far, it is about as far from an indictment of Christian sexual morality as you could hope to find, given that it is written by an atheist who practices male love. Not homosexuality. Foucault thinks that homosexuality is a product of the modern psycho-medical concept of sexuality, but that's an entire blog entry in and of itself.