What I do find peculiar, is the argument that goes along the lines of, “Well where I live, I don’t know anyone who earns £x, therefore you’re all making it up.” 
I don’t know all sorts of demographics of people, yet I’m still 100% sure they exist 
I think people live in their own bubbles a lot of the time. I’m guilty if this, to be sure. For instance, I genuinely never realised that anybody held strong views about women who are long-term SAH, until I came on MN. Round here (which is where I’ve lived since having DC) it’s the “norm” really and I don’t know anyone who uses daycare centres. So when you read some of the vitriol on here, it does jolt you and you realise you really are in a complete bubble.
But that’s why I like MN because there’s such a wide variance of people and that’s exactly how it should be.
People may make things up, but this could be said of any topic in here, surely? Maybe they claim they have a DH when they don’t; or they claim poverty just to get a reaction. Anything is possible really. From my perspective, there are more threads that seem to be a “race to the bottom,” than anything else. It’s far more “acceptable“ on MN to be anonymous and in poverty, than anonymous and wealthy, that’s for sure. Same with anything relating to DC, If I said my DS got all grade 9s at GCSE, the reaction would be that I was “stealth boasting”. You see all the time that when people are honest and say such things, they feel as if they have to quickly balance it out with, “oh but he has other difficulties /issues, etc - otherwise they’ll be jumped on. I think some people may exaggerate, but equally, other people may feel the need to hold back on the truth for fear of inciting resentment or it sounding insensitive.