Google's IOS Chrome browser has introduced image compression so maybe using this will alleviate the Apple webkit restrictions.
I was noticing that there are also plenty of reports that the Google maps api has the very same problem.
I'm fairly certain that Nokia Here got removed because of the new memory restrictions, that being a web app.
remembering that Nokia said 'IOS 7' effects user experience, they likely did not see any gain in rewriting to adhere to these new limitations.
Whether instigated on purpose,, it really appears to be Apple pushing developers to write native apps rather than use cross platform friendly web apps.
I never did quite believe Google's argument about forking webkit but looking at it, as Apple's garden walls expand, the web is more and more being seen as the main weed that stunts income growth.