I think if Apple really really wanted to implement it if not for the risk to app sales, they'd have it on desktop Safari, at least. As it is, I just think they don't want to implement it, App Store or no.

From observing non-geeks use the "feature", I think that's the right call regardless. It needs to go back to the drawing board, or be scrapped. In general, anything that expands the reach & capabilities of websites should be treated with a ton of suspicion, as a likely vulnerability vector (leaking tracking info; social engineering/phishing vector; straight-up exploitable bugs) or simply a net-negative annoyance for most users.