Well there are more than 1000 apps added in the phonegap.com library built with html for ios. While that's negligible it's certainly not to be frowned upon. There are some big names too.. check the featured apps.
This always comes back to the same arguments, we had this conversation multiple times now. Yes native is better, but you can still build a good quality app with html compatible of multiple platforms, specially if your app is only a text crud.
But in the case of Appcelerator they seems to certainly do not want open technology like html5 to win & prefer selling their tech.