I think it's a bit of both. Some folks a gullible, then there's the "must have new toys" mindset. There's a hard sell for stuff, help to buy new homes, etc. We're now a few generations away from those that were adults during the Depression, and I think those lessons are mostly forgotten. I could be wrong, but most stores would much rather you buy on credit than use lay-away.

I remember buying a house in the 90's and being pushed to get a "3,2,1 buy down" type loan. What stuck in my mind was that I'd owe more money at the end of 3 years than on day 1. I thought that was pretty stupid, and got a conventional loan. Did that stop the sales rep for the development, NOOOO.
"You'll be able to furnish your new house, decorate... Have it all now, don't wait! Refinance in 3 years!"
No thank you, I'll be conservative now, and not hate you in 3 years.

I could hear my Grandmother saying "make do or do without" "waste not, want not"