It's also possible that some of these aren't that bad in context. The Cornwall and Trevelyan book (the one with the "vaginal ratchet") is actually a satire.
And I think Murukami's rapey one was supposed to be a surreal dream sequence? (I haven't read the book; that's just some hearsay.)
That's always the delicately-ignored issue when this award comes out; a
lot of sex scenes, even very good ones, are awkward as hell if read out of context. Surprise-porn when you're not in the mood is not welcome to most people, including people who enjoy it when they
are in the right frame of mind.
The author has presumably warmed the reader up a little before the characters get busy, so it's not really fair to read these excerpts cold. Of course, the humour of the award mainly comes from how spectacularly cringey those scenes are out-of-context, so maybe even though it's not fair, it
is fair, given what the bad sex award really is -- an exercise in ridicule.