Microsoft was openly hostile towards Linux for many years, with former CEO Steve Ballmer famously saying, Linux is a cancer. This hostility was understandable, when we consider that Windows was its main source of income for Microsoft and Linux was the direct.
Over the last few years, Microsoft has diversified its product palette, especially their cloud services. Then, in 2014, Microsoft open sourced the .NET Framework, something that couldn't have been expected during Steve Ballmer's tenure. Even with this development, the announcement that SQL Server would run on Linux came as a shock and seemingly out of nowhere.
The idea behind this move is to allow anyone to install and use SQL Server, regardless of the operating system that is being used. This is already being offered with containers, in that the container process can run on Linux or Windows...