As someone who does web development, and has been doing it for longer than the last couple of decades, that statement seems unnecessarily dismissive.
> But most of the web pages that people use day to day are not "documents", they are apps.
While I would agree that the quantity of web pages people visit today that are 'apps' is substantially larger than it used to be, I do think there are a lot more plain HTML documents in use (particularly in boring corporate environments) than many who frequent HN would think.
Of course, if you are going to call anything that executes a significant amount of Javascript an 'app', I am not sure I'm interested in the argument.
My original response wasn't arguing about what was most common anyway -- you said "Web browsers are not hypertext documents viewers anymore." I was just pointing out that they still do a lot of that (and for things that I would not consider to be an 'app'). Admittedly the line between 'app' and 'document' is a bit fuzzy in some cases, but there are enough cases where (in my mind) it is not fuzzy that I still don't see your original comment as accurate.