This thread reminds me of a guy I used to work with who was perpetually in bleak amounts of debt, got a big tax rebate amount from an old job and immediately bought an outlandishly expensive massive animatronic dancing James Brown dummy. To quote my supervisor at the time "Oh, Barry!"
I have two friends who do this on a slightly different scale. One of them was actually homeless for a while a few years ago after months of sofa surfing, and now lives in a slightly derelict caravan, busks for a living and often asks friends for 'loans' (never to be repaid), but as soon as he gets slightly more money than he needs for food or phone credit he spends the lot on records and (unnecessary) clothes, and has in the past posted photos of his latest purchases on facebook so all the friends who just lent him £50 can see. The other is always going on about how much spiralling debt he and his wife are in, how much they'll never get out of it etc., but then in the next breath he'll be buying a new guitar, or amp, or pedal (and not cheap ones either) presumably on a credit card.
I get how when you're skint and/or in loads of debt, that treating yourself can make you feel better even when you know you shouldn't spend that money, I've certainly done it myself, but the difference is I didn't moan endlessly about being skint, or borrow the money, or post about it on social media. I keep my shiteness with money to myself thank you very much, just seems like common sense rather than literally inviting people to question your poor financial logic.