Essentially because they're easy to grok. Take js for example. No interfaces, basic OO system, no access modifiers or static typing, no multithreading, no point

Essentially because they're easy to grok. Take js for example. No interfaces, basic OO system, no access modifiers or static typing, no multithreading, no pointers Etc... A lot of concepts can be handwaved when you're using a language that doesn't support them. Js is easy to learn and widely useful.