Googles explanation - i.e. dump android in preference to its own mobile OS
'.. If the affected version [of WebView] is before 4.4, we generally do not develop the patches ourselves, but welcome patches with the report for consideration. Other than notifying OEMs, we will not be able to take action on any report that is affecting versions before 4.4 that are not accompanied with a patch ..'
http://www.neowin.net/news/after-throwing-microsoft-under-the-bus-google...