I mean a lot of programming language design goes back decades; it's better to focus a course on the basics that every language will have vs the most recent developments that haven't fully crystallized yet either.
There is a critical difference between programming language design and compiler design.
You are right when it comes to programming language design and somewhat wrong when it comes to compiler design.
If you are doing compiler research/development, you have to be familiar with the latest and greatest research because the margins for improving things are fairly slim. It’s usually fine to be not familiar with how things worked ~30 years ago.
For programming languages, you absolutely have to understand the foundations to do absolutely anything.
> If you are doing compiler research/development, you have to be familiar with the latest and greatest research because the margins for improving things are fairly slim. It’s usually fine to be not familiar with how things worked ~30 years ago.
On the other hand, if the margins for improving compiler quality are slim they can be ignored without great consequences: it makes sense to study state of the art research only in the niches that turn out to be relevant for a specific need of a specific project, not blindly and at the expense of important general principles and techniques (i.e. mostly the problems of 75 years ago and the solutions of 25 years ago).
Again this is not necessarily for someone doing compiler research, but foundational knowledge for anyone at the PhD level.
Someone doing compiler research this might be a first graduate level course to get them used to the technique and concepts used in more recent research for the might have two or three additional courses getting closer and closer to state of the art.
