Apps that exist are better than apps that don't exist. Ask WebOS users, the few that still are out there. The only way to make web apps as nice is to put the engineering effort into making them as nice (something only Mozilla is seriously doing at this time). Another proprietary mobile ecosystem isn't going to be adopted.

I don't understand your argument. A new platform has to offer something the existing platforms don't have. Web apps cannot be the differentiator for a new phone OS because the big two already have standards-compliant web browsers. The browser is table stakes; of course any new phone OS must offer one, because you can't be taken seriously without it, but the browser in itself is not a reason to use the platform.

Or are you suggesting that new phone OSes ought to add proprietary non-standard browser extensions in place of a native apps API? Given the ugly history of proprietary browser features it is difficult to imagine anyone taking such a strategy seriously.