> It's down to the pool being bigger (development pays well so career chasers do it) and survivor bias for old developers. The "bad" younger people either get found out our talk their way into management, or they find a niche and becoming unmissable in their company (and can never leave).
I think it's more because of motivation to become a programmer. A few decades ago (or even until maybe 10 years ago), programming wasn't that prestigious, you only did it with an honest interest in tech. Tech today is what Investment Banking and Law was a decade ago, the way to make a lot of money quickly in a fancy job. That will lead to many people going into it that are highly intelligent (and therefore able to produce code) but not motivated to produce output that will function well even after they left the company.
I think it's more because of motivation to become a programmer. A few decades ago (or even until maybe 10 years ago), programming wasn't that prestigious, you only did it with an honest interest in tech. Tech today is what Investment Banking and Law was a decade ago, the way to make a lot of money quickly in a fancy job. That will lead to many people going into it that are highly intelligent (and therefore able to produce code) but not motivated to produce output that will function well even after they left the company.