*it is just about impossible to use the word in anything but a jocular or pedantic (or hackneyed!) context

Technically speaking (or writing), indeed you're correct, tsuwm. But otherwise, I think you're failing to give "sex" due credit. Even if it is overvalued!

(I'm assuming in what follows that appending the word to others is acceptable practice, by the way. Correct me if I'm wrong)

First example that comes to mind - unfortunate in that it's an invented word - is "sexcrime", a bit of Orwellian newspeak. Not much jocularity, and quite a lot of bite, in that one.

"Sex slave" sounds ironic or jocular at first, but then goes a bit sour.

"Sexy" - definitely overloaded, and well detached from its original meaning. Or is it? Maybe we're not giving due credit to the diversity of the original meaning!

(starts getting quizzical looks from the audience)

Actually these are bound to be personal impressions, but that's maverick's point, isn't it? Those impressions can swing to extremes, and there are acres of interpretation between those extremes which can be weighted by context. Even if that context is a single word.

Great stuff! Exactly what the English language is all about, in my humble opinion.