Perhaps, but then one would have to assume people weren't being honest. Most of these ladies read a lot and in addition to book club they pass books around once finished. Some of those books have the odd steamy scene, so it's not like it's outside of their realm. So, I actually believe them when they say they don't prefer to read about sex in detail.
I also doubt that so many best-selling authors would avoid it, if they thought people wanted it.