Why aren't NodeList / HtmlCollection seqable?

You have to think that clojurescript is a compiler to javascript as a language, not only browser JavaScript. You can also use it in other platforms like nodejs or with the QT library where NodeList does not exist (because it is part of the Dom api and not the standard language).

If you are looking for a way to create a sequence from a NodeList there is array-seq function.

(array-seq (js/document.querySelectorAll "div"))