Web apps tend to be simple enough that hot keys usually don't make sense. If your web app isn't simple, it probably shouldn't be a web app (HTML doesn't handle complexity well).
Umm, I use hot keys so much that web interfaces irritate me because I actually have to move my hand to the mouse. Trying to use keyboard navigation for web pages is painful at best. It doesn't matter how simple your web pages are, the keyboard is just not a good tool for web page manipulation, and when I'm working I prefer not having to use the mouse.
Don't get me wrong I surf the web as much as the next person, I just usually don't consider it work per say :) I use a mouse a lot too, I just prefer not to when I am typing a lot or "in the zone" as it were :)
So in a sense I agree with you, web apps are not always the best tool for complex applications :)
"Nothing is sure but death and taxes" I say combine the two and its death to all taxes!