Aside from the competitive strategy of balancing office suite and mobile platform sales, there's the matter of limited resources. The statement from Google doesn't really sound like sour grapes over offering its software on a Microsoft mobile platform as much as it seems like a calculated decision about how to use resources most effectively. Windows RT and Windows Phone 8 are simply not a big enough market to warrant the effort from Google.
What does that mean for you? Well, it means that you need to consider what office productivity software is available for each mobile platform, and factor that into your tablet purchasing decisions. If you rely on Google Apps, a Surface RT probably isn't the best choice right now, and if you depend on Microsoft Office, you may not want to buy an iPad or Android tablet.
It would be nice if the office suites were more platform-agnostic and you could get Google Apps or Microsoft Office apps no matter which tablet OS you choose, but that's not the case -- at least not yet. For now, you need to consider the bigger picture of how you plan to use the tablet, and which tools or applications you will need to interact with in order to choose the tablet that will work best for you.