I've worked with engineers implementing Salesforce at two different companies. While SF may or may not be the right solution for a problem, I disagree with you

I've worked with engineers implementing Salesforce at two different companies. While SF may or may not be the right solution for a problem, I disagree with your assertion that developing for Salesforce will in any way prepare you for a "real" programming job. You would mostly learn how to configure a lot of UI, maybe write some custom widgets (with Lightning), and write a a little bit of integration code here and there - in an arcane Java-like language. All you really learn is the Salesforce ecosystem. You can make very decent money if you can sell yourself. As others have mentioned, Salesforce could be seen as a sophisticated employment scheme for consultants. But I would advice anyone to steer clear of it as a career path. At least until you have some proper experience in other technologies.