You could also argue that Safari on desktop is more likely to be updated as well since it is generally accepted that Mac OS X has a higher adoption rate of new

You could also argue that Safari on desktop is more likely to be updated as well since it is generally accepted that Mac OS X has a higher adoption rate of new versions since: 1. enterprise use of Mac OS X is pretty small, and its generally enterprises that are slow to upgrade OS/browser, etc (albeit for generally valid reasons) 2. OS X upgrades have been free for some time now.