I think it is perspective. I would prefer a web where I can use any language I want and not be forced to use only Javascript to create content. So in that sense this could give me more freedom.
For example I may chose to write my code in Rust and that imposes a burden on you (assuming you know only Javascript), but it does not curtail your freedom. Not as convenient as before for you since you now need to learn Rust. I think the freedom has spread to the person who is creating the content (code). The general consumer does not care, but the tinkerer/hacker now needs to put in more effort to parse the creation.
I agree that giving authors more freedom is a good thing, but as I argued, it also has serious downsides. But I think there are ways to keep the best of both worlds. I wrote a comment here with more detail: https://news.ycombinator.com/item?id=9743859
For example I may chose to write my code in Rust and that imposes a burden on you (assuming you know only Javascript), but it does not curtail your freedom. Not as convenient as before for you since you now need to learn Rust. I think the freedom has spread to the person who is creating the content (code). The general consumer does not care, but the tinkerer/hacker now needs to put in more effort to parse the creation.