It's free....
And like all free things, regardless of source. It is a lure, a hook, bait.
It will have use for some in free format, it will earn revenue from those who want more. Makes no odds to me, I manage to communicate with my clients well enough using pdf, odf, plain text, txt msg and word of mouth.
I don't need Microsoft for anything either, others do. They are called consumers, they don't think much beyond convenience, some don't think much at all. So if it is convenient, free and easy to get/use then it will find a user base. It just won't find one here.