If you want to use web based technology, embed WebKit instead of Chromium. I'd think there would be huge memory savings, since the OS only has to load one dynamic library for N web-wrapper apps, as opposed to one Chromium instance per app.
The most likely reason developers don't do this is that it isn't really about targeting web-based technology. It's about targeting Chrome.
The most likely reason developers don't do this is that it isn't really about targeting web-based technology. It's about targeting Chrome.