Because sites that distract me from what I'm reading to tell me that there are new comments are extremely annoying.
Sure, you could add, say, auto-loading for new comments when you reach the bottom of the page, or setting the message icon to orange when you get a reply, but that hardly requires a full-blown web app, it's a simple addon to a static site.
Sure, you could add, say, auto-loading for new comments when you reach the bottom of the page, or setting the message icon to orange when you get a reply, but that hardly requires a full-blown web app, it's a simple addon to a static site.