> Yet most Chrome users have not ever opened Chrome Web Store
Web Apps != Chrome Web Store. Web apps are just websites, that's all that B2G "apps" are. If you use Chrome or any web browser, you are using "web apps".
The interface for accessing the apps might be more "appy" with the Chrome Web Store". But even without that, websites like gmail are "apps". "Pin as app tab" for example is nothing to do with the Chrome Web Store, but it is "appy".
In fact, the Chrome Web Store doesn't have real websites in it. They can't do stuff normal websites can, for example they can't use Facebook Connect.