In real life, consenting adults get up to some far more experimental behaviour and a lot of other writers go into far more unnessecerry detail, and far more often.
Correct: consenting adults do do all sorts of things. However, when everyone joins in with everything, as seems to be the case in the latter stages of SinSL, the book loses any sense of tension or narrative drive. That the "conversion" of the mildy doubting is so simplisticly done, driven by straw men easily vanquished, simply meant that I lost interest in the story.
(None of this has anything to do with the views expressed, or any particular view of women. Frankly, if those in the sect had agreed with every single view I happen to hold, it would still not have made the latter stages of the book a better read.)