In brief, my opinion is that all the reasons Hannah gives in her blog are well considered, fully explained and genuine. I don't think it's any kind of knee jerk reaction - if it were, there would be no need for her blog to be so detailed. Some aspects are things she has talked to me about, others not, but I have no reason to doubt anything she says.
Of course I am very happy that she will continue to see those she feels she can trust not to take the piss or push the boundaries; she has other strings to her bow and has clearly worked hard to get herself into a position where she can make such a choice.
For the record, my experiences with her have only improved over time, as I think my recent review demonstrates. I've never detected any hint that she was getting jaded about sex in general, but I can see how dealing with the kind of fuckwits and boundary pushers she describes would give anyone in her position pause for thought.
For me it's quite simple: her body, her choice.
MrB