Sure, you can quote such examples, but they are more in line with individual failings, rather than group failings. Call them, "negative and destructive" choices, instead of what I would call "inferior" choices.
Most people who don't do well aren't particularly bad, they just make inferior choices during their lives. Things such as "Do I study or do I party?", are really decisive for a lot of them. Many lack the will to make hard choices to do difficult things that will improve themselves. Eventually they fall into dull routines that guide them away from success.
If their culture raises them to be losers, or to have low and unimportant roles in society, odds are that they will grow into such roles. Some will escape, of course.
I can not disagree with your logic.
However, some groups are real losers. Yes there are the 10% to 20% that are really achieving. I do not know what the cause, genetic, cultural, hate filled, or whatever.
I have made my choices and have held the same job and worked real hard at it to support myself and me family.
I do not have to pay to keep someone alive because that person did not feel like working, studying or other things that are related to keeping alive.