Why Microsoft should buy Unity3D?

So why should Microsoft buy it?

1. We want to maintain a single standard for a gaming platform. Windows 10 is the standard.
2. Give Windows/Xbox games the leading edge API head start(DirectX and .Net components)
3. Improve performance on own products first.
4. Break the "app gap"
5. It's growing.
6. It's a great model for our Universal Apps.
7. It's attractive to developers.
8. This tool works well with otheres

Yes, it's monopoly but it's a great way to move forward.
I'm putting my vote down. Will you?