Especially for those who are do not do well in English grammar or comprehension, using Microsoft Office in writing your blog posts would significantly improve the quality and accuracy of your articles, as Ms Office has spelling and grammar checker.
And for those who want to make their articles a little bit more professional, you can use the synonym function of MS Office to look for other more profound words instead of those which you thought of yourself.
Using MS Office would also improve your speed of making your articles, as you do not need to worry much with the mistakes, as errors will be automatically detected and underlined so you can just look for those errors and modify them easily. I myself use MS Office in writing my posts, especially those lengthy ones. And it makes me feel more satisfied with my English composition.