Yeah I do find it super weird that people do this.
I think front end rendering is well suited for internal tools or tools that you must login (gmail, google docs, etc..). Anything that is front facing and/or require SEO shouldn't be frontend rendering javascript unless you can afford a fallback with it.
It's really not that wierd. This is the first time I've seen anyone mention the lack of non-javascript support, or mention that the site doesn't work because of it.
I think front end rendering is well suited for internal tools or tools that you must login (gmail, google docs, etc..). Anything that is front facing and/or require SEO shouldn't be frontend rendering javascript unless you can afford a fallback with it.