His point is that HomeScreen web apps (for lack of a better term) are fundamentally exactly as secure as MobileSafari.

Even a technical argument is somewhat hard to fathom, since it should be a trivially simple thing to enable, but given that none of us can see the code it's at least possible.

As far as native apps with embedded UIWebViews, this is a believable technical argument, though it isn't obviously true either. In other words, the political argument isn't significantly less likely than the technical one.