"But the flaw in your analysis is that all sex is forced or unpleasant." Well no wonder you disagree. jamesjohnson did not say or imply that all sex is forced or unpleasant. Please show me the part of his comments that say or imply that. I am just no seeing it.
Assuming that you are reading his comments that way, I believe you are presupposing their meaning and then developing a defense. You defense is logical, but your premise that he said that is an error.  I believe the term is a priori reasoning, meaning formed or conceived beforehand.
The flaw is not in the analysis. It is in understanding what he wrote.