[SiVal]

slow to follow the standards

Safari is not only slow to follow the standards, it is slow to advance the standards. I'd be more likely to believe the spin that Apple just wants to make sure things are done well on the web if it appeared that they were trying as hard to add good, new capabilities to the web platform as they are to add good, new capabilities to iOS.

A engine that isn't Chrome is very essential for keeping the web open

Also essential is for the open web to be competitive with closed alternatives, or the fact that it's open will matter less and less. Apple is quite willing to provide competition for Chrome. It does it with iOS.

[greggman3]

Apple is only able to do this because of the monopoly of browser engines for 1.5 billion iOS devices. If they allowed (or were forced to allow) other browser engines then likely a large number of users would switch to another browser, forcing Apple to compete for features.

[manigandham]

What's that say about the quality of Safari then?

[rimliu]

How quickly people forget who brought canvas, CSS animations, etc.