But this is also to do that many people do not see developing software as a career; more something they happen to be ok at and it makes a bucket load of money.

But this is also to do that many people do not see developing software as a career; more something they happen to be ok at and it makes a bucket load of money. If it's a career, like I decided to make of it when I was 16, you can be an actual senior in a number of languages. I feel equally secure writing large codebases/projects in quite a substantial number of languages after 30 years of learning different languages and environments and having and worked on many large and different projects using different languages. It is quite different for someone who is 25 and does not get enthusiastic about spending a lot more years in the field; why would you then learn a lot of different languages? It makes more money, short term(!), being good at one language just jumping up the ladder as fast as you can using that.