That is weird. AbuseFilter now uses CodeEditor, but CodeEditor is supposed to show you the textarea when JS is not enabled. Somehow, it doesn't (the textarea is there if you look at the page HTML, it is just not visible).
I'm currently working on this. Apart from the philosophical matter itself of disabling JS, AF strongly relies on it. With JS disabled, for instance, you can't perform syntax checks, the action checkboxes are all expanded and you can't use /tools.
It makes me wonder if MediaWiki itself officially anounces that it requires JS or not. I couldn't find the answer by a simple search; let me go ahead and ask it on mediawiki-l