Just look at the screenshot picture in the article. One third of Edge's windows is just ads for games.
Remember the days of IE 6-7 when you'd get them infested with toolbars and adware as every Windows app you'd install would try to sneak those in during the installation process if you weren't careful to untick the right boxes? I guess someone at Microsoft though "hey, what if now we were the ones pushing the adware to our customers and monetizing their data?".