The problem is that arguments from both sides are often generalized and it's not necessarily wrong. If you have a wide audience e-commerce enterprise you should probably keep JS use as limited as possible. If you build tools for programmers or highly dynamic projects, JS everywhere is probably fine.
If you build tools for programmers, give me some way of interacting with it other than running your JS in my browser. Otherwise, I'm likely to find it horribly awkward to integrate with my preferred workflows, and I'm unlikely to use your project.
The problem is that arguments from both sides are often generalized and it's not necessarily wrong. If you have a wide audience e-commerce enterprise you should probably keep JS use as limited as possible. If you build tools for programmers or highly dynamic projects, JS everywhere is probably fine.