>iOS Safari W3C non-compliance is well known, a little googling will lay out the (intentionally) missing features.
The illogic here is a little scary: Firefox and Safari on iOS basically have the same level of web standards compliance according to html5test.com, yet one is intentionally not implementing features?
It's not that surprisingly that the one making the decisions about the browser engine is blamed, not the one forced to use the browser engine instead of their own, is it?