Not at all, there's a certain level of sensibility in client-side rendering -- particularly because responses can contain only a skeleton structure of content, ie: JSON.
Relying on a client-side language that may (or may not) be disabled, however, is simply foolish.
But roughly speaking HTML should contain the structure, and CSS the rendering information, especially if it's mostly a static page like here (maybe if you're writing a Webmail client or something it makes sense to handle more stuff on the client side).
I guess the absolute horror scenario for the web would be when people start deciding to do their own personal server-side markup, and then render it with a bloated JS library on the client (hey, it's Turing complete!).
Relying on a client-side language that may (or may not) be disabled, however, is simply foolish.