That's because Windows and Office are still their big cash cows.
Want to use a PC? You use Windows. Want to write documents and spreadsheets? You use Office. They have a massive monopoly on those two things, and right now they are coasting on inertia. If people don't like Windows 8, what do they do? A few switch to Apple. Fewer still switch to Linux. The vast majority just stick to Windows 7. In other words, Microsoft still makes money even if they fuck up royally.
But as soon as you step outside that core, look what happens. Practically every single venture they have attempted, has flopped on it's face. XBox had a good run, but Microsoft did an excellent job of torpedoing that with the XBox One. Remember Zune? How many BILLIONS have they lost on surface now?
The *only* thing that is keeping Microsoft afloat right now is that core Windows/Office property, because it's not worth the effort to switch away from it. But for anything new, people are generally avoiding Microsoft like Typhoid Mary. As they should, given the number of entities (and I'm talking Partners, OEMs, and even international standards bodies) that Microsoft has screwed over, only a fool would trust Microsoft to so much as squeeze their raging blackheads.