I think she meant that too. But the reason it is catching people wrong (and there's no reason amillion would have known this, I'm just saying I'm pretty sure this is what's bothering people) is that it's a fairly common sort of truism that is said when men do something nasty. 'Why did he feel so alienated from society?' 'Well, perhaps the problem is he didn't feel loved enough'.
I'm seeing these comments on my facebook pages after those awful news stories in the US and over here about men who, very tragically, killed their families and then themselves. So, it did make me think a bit.
Obviously talking to people in the street is a totally different order of activity (!!), and I can see why someone friendly will think it's best just to treat everyone as if they've perhaps been rude for some reason, and to be nice back. I don't think this is a gendered principle - if someone snaps at you bagging up your shopping and you're this sort of nice person, you'll probably tell yourself she or he is just tired or cranky, and you'll be nice back.
The reason that - for me - it becomes a bit uncomfortable is this association that practice of 'being nice to strangers' has with women. I do think women are expected to do a lot of the 'being nice' and smiling (hence 'cheer up love, give us a smile', being a comment typically made to women, because some men like to think they ought to be able to make women smile). There's a very Victorian/Edwardian idea (which my granny would have loved) that women are naturally better at adding a little social ease to situations, that they ought to be sociable and pleasant because everyone likes a smiling girl and it cheers up the men, who're naturally more gruff, what with their Masculine Natures.
Ok, we can snigger now, but I do think the vestiges of that attitude are still seen in everyday social intereaction. And I think at their extreme, they come out in these reactions to the tragedies I mentioned above, where people wonder what the woman didn't do, that her partner or family member killed her.
Sure, it's a completely extreme connection to make and I stress I'm not comparing the two situations ... but that is what amillion's phrasing happened to make me think of, with its language of 'not being loved', so I thought I'd put it out there in case it helps explain why some posters are reacting to it a bit.