Why would I pay someone to trash talk my product or recommend another product? Coke would never have their polar bears drinking a Pepsi. Even Chevy ads don't talk about Cadillac.
I'm not sure whether you're joking or serious. Of course, a company won't praise a competitor in their ads. However, the money Microsoft hands out is for videos that are not presented as advertising at all. Instead they want regular users to do "stealth advertisement", when it is NOT clear to the viewer that those guys were paid by Microsoft. I would have no problem with Microsoft paying for ads that are clearly identified as such. You know, the stuff you see on the web or on TV.
The part I was highlighting is that Microsoft has a clause saying if you receive money from Microsoft, you can't talk bad about them. That's pretty natural, they don't want to pay detractors to keep disparaging them.
