Microsoft already has Visual Studio Team Services, which is its Git-compatible source code and work-item-tracking system. Like GitLab, VSTS is focusing on enter

Microsoft already has Visual Studio Team Services, which is its Git-compatible source code and work-item-tracking system. Like GitLab, VSTS is focusing on enterprise sales first (though there is a free-tier that you can play with). Why would Microsoft want to buy Github and try to refocus it when it already has a product that caters to its enterprise clientele?