To me it's not about buying something you can't afford. You aren't getting underwater with these phone leases. Just think of it as part of your phone bill.
I certainly do get that, it would be really interesting to see some socio-economical data on how's buying a phone vs. who's simply renting it through these plans. It's part of your plan but you never own that device, you cannot simply sell it and use that money when needed, that's one problem IMHO.