For them, it's nothing about compensating for anything, it's about wanting to maintain an appearance of wealth. As it is/was for so many people.
I agree with this, however, I think people are so keen to see the fault in others, they don't look to themselves. Many of my friends are mortgaged up to the hilt with large houses, big gardens, extra bedrooms, kids not sharing bedrooms, all those things are also luxuries (i.e. not necessities) and also paid for with borrowed money. It's just they got lucky that their number wasn't called when the recession hit. Others are smug as they bought a long time ago and so have small mortgages. Again, lucky them.
It's easy to believe that you are very prudent and others are spenders, and indeed, there may be some very prudent MNetters who were both fortunate and sensible in buying their houses/spending their money. But as I say, most homeowners weren't (hence the negative equity) and they need to silently thank their lucky starts mortgate rates aren't spiralling (yet) instead of going on and on about all these people who had luxury holidays whilst they were oh so prudent when getting into debt for their larger than strictly necessary 'luxury' houses.
Not that I have had either a luxury holiday, or a big house, or indeed have been bankrupt, but I hate the smuggery around blaming others for their spending ways on MN- most people overspent, that's why we are as a nation effectively bankrupt (and have to keep borrowing at high rates).