Microsoft doesn't refuse open standards, in fact they are adding CalDAV support and embracing HTML5 and CSS. They made it a first class language in Windows 8. Google was actually about to drop CalDAV as well as EAS. But they received huge backlash for that.
Google is the one that dropped the support with little warning. Google is the one blocking the YouTube app and refusing to build apps for Windows 8 or Windows Phone.
Microsoft is the one updating their integration constantly chasing Google's moving requirements. Microsoft is the company that has made their apps for iOS and Android including, Word, Excel, OneNote, SmartGlass, Xbox Music, etc.
I'm sorry, but in this case, Google is the one being the ****** bag and stiffing their own customers.