My reading of the thread:
OP-trying to be lighthearted about motherhood experince in supermarket.
First response to OP is Aitch- dismisses OP's point in a way which appears to be a snub due to brief nature of the post and minimal language used and fact that it's the first response.
OP- responds to snub, as poeple tend to, with hurt feelings.
Aitch -hen responds to hurt feelings with justifaction that OP is offensive to women struggling to have chilren and that it's not funny.
I would say-OP obviously has nothing to do with women struggling to have children and it's pretty unkind and obviously hurtful to tell some one who is tyring to be funny that they're not. You'd have to pretty lakimng in empathetic skills to not know that.
You usually come across across as very empthatic actually Aithch, so I'm suprised at you're dogged instance in this case that refuse to see the other side.
AS I said I actually think the timing of your post is what has created the Woo-Haa and it would have recieved little comment agmonst various types of responses.
As is often the case a little exchange along the lines of 'sorry Nina didn't mean to snub you just didn't recognise the type, or situation, you describe'
followed by
'no worries, I was unawere that offensive would be taken by word Childless, and I certainly didn't mean to upset anyone with that'
followed by
'no worries'
would wrap the whole thing up and make the reat of us redundant.
I'm always suprised by attitudes on MN who refuse to acknowledge upset and use the 'that's how it is line'.
If I've upset someone,particuarly uwttingly, I usually want to make it better, unless I'm really pissed off with them and wanted them to know this.