This is the harmful misunderstanding part. Many systems in society are designed, intentionally, to perpetuate the defeated state that poor people randomly find themselves in.
The manifestations of systematic poverty are not really free will choices of poor people a lot the time, from poor financial investments, poor purchase choices (especially when it comes to dietary choices or purchases for children), poor investment in education. The whole world they inhabit is institutionally configured to perpetuate this, give them no empathy or support.
To a good first order approximation, zero percent of the life situation inhabited by most poor people is “their fault” and most outward seeming bad habits that are lazily easy for us to judge are really things we, society, have pushed onto them, and we should not take the easy way out and think contemptibly towards them.