I think of the following quote whenever I hear someone, such as in the media, remark that the Catholic Church is "fixated on sexual issues". I was reminded of it again yesterday by a post on Mark Shea's blog when he made the same point. Anyone who actually knows anything about Catholicism, of course, knows that criticism to be a matter of projection on the part of the critic. The fact that the media seems to be fixated on whatever the Church states on those issues, and ignores the million other things that the Church is concerned about, shows that any "fixation" on such issues resides in those who report.

And Chesterton's quote here, though in context written about how some Protestants do so in regards to other issues, still describes the same general attitude of the media mentality mentioned above, specifically the part of the quote that is bolded: 

…the Church is generally seen in the light of the last heresy. The Church is supposed to consist chiefly of the things of which that heresy happens to disapprove. So much of the Protestant tradition still remains that a great many people suppose that the chief marks of Catholicity are those which stood out as stains in the eyes of the last school of critics. Romanism is supposed to be made up of Popery and Purgatory and the Confessional, with the queerest things thrown in, such as incense and rosaries and the images of saints. But these were often the things most important to [these opponents of Catholicism], not most important to Catholics; and not most important to the other opponents of Catholics.

-The Well and the Shallows (1935)

Or, more briefly, as Chesterton puts it in The Common Man (1950)

The Catholic Church is always being defined in terms of the particular quarrel that she happens to have with particular people in a particular place.