True. My personal site is static (generated with Hakyll), and uses Disqus for comments (only because I haven't yet seen a simple, self-hosted alternative which has been battle-tested).
I work on a statically generated site in which the comment form simply feeds back into the generation workflow. It's certainly not 'battle tested', but it has the advantage that a) we get to own the comments rather than giving them to someone else b) everyone can partake in the discussion c) much less demand on the client when rendering