The security and platform lock-in risks are really quite high. An attacker who finds a security flaw in Android being able to silently run their code on devices

The security and platform lock-in risks are really quite high. An attacker who finds a security flaw in Android being able to silently run their code on devices, from web-sites, means that system attacks can then be done drive-by from the web. I really hope there's an opt-out for this feature.