My personal take is that there there is a difference between :
'things people say that aren't specifically insensitive but I find difficult due to my personal circumstances'
'things people say that are insensitive'
Neither are intended with malice. Neither falls into the 'I'm sorry you are offended' pass agg (I have said something offensive but I refuse to acknowledge this and therefore I will deflect the blame onto you for being offended rather than taking accountability for what I have said) camp.
I believe the KW comments fall into the former camp. I might find them difficult, but that's all on me because I am conscious of feeling lesser than in a society where the childless are often treated as second class citizens. I don't believe they are specifically insensitive per se
I do however think it is insensitive to repeatedly use these comments as an example of the importance of validation for mothers, on a thread about what not to say or do to be supportive of childless women. I refer to margaret's brilliant academic example
I do think it is offensive, rather than merely insensitive, when comments about childlessness tip over from thoughtlessness about the situation of childlessness, to judgemental comments about a woman on the basis of her childlessness
For example - Andrea Leadsom, when she used Theresa May's childlessness as a stick to beat her with, saying that 'as a mother' she could understand the need to protect the next generation's future in a way that May could not. There are many many many reasons to criticise Theresa May's competency as PM - I do not believe her childlessness is one of them.
Another one. When the New Statesman published a cover of Liz Kendall, Angela Merkel, Theresa May, and Nicola Stugeon, around a ballet box inside a cot, asking why so many successful women were childless, with the undertones that childless women are avaricious career women who selfishly prioritised their careers over having a family. As it happens, both May and Sturgeon have spoken publicly about their experiences of infertility and miscarriage, and about their sadness at never having had childre. But whether these women are child free by choice or childless by circumstance is entirely irrelevant - it's still vile and reinforces prejudiced stereotypes.
I do NOT believe that the KW comments fall into this category. But all I would ask is for people to show a little awareness about where is most appropriate to discuss the question of giving mothers validation, and a little kindness to those who will never be lucky enough to be able to validated in this way.