Well, I'm working in HFT - not very many exchanges speak HTTP.

Web browser tech itself quite obviously can't all be built as a web app.

A lot of things could be built as a web app but it's plain silly to - I don't want to lose access to my text editor when I lose networking (I could run a server on my local machine, but that's several layers of abstraction that clearly aren't necessary and I'm not confident they're helpful).

To be sure, there are lots of things where a web app is quite appropriate - but a view that that's all there is seems myopic.