BTW if you reply to this comment with a "Microsoft smackdown" comment then your comment is not very interesting.
I'm interested to hear some thoughtful replies, not Linux fanboy pile-on and jeering.
Come deployment time, they decide to deploy on Windows to minimize unnecessary differences with their dev stack and there are better deployment tools for MSSQL on Windows than on Linux.
I don't think Microsoft is trying to stop people from using Windows as a back-end server (especially when you look at efforts like Windows servers as Docker container farms), more that they are trying to even further lower the barriers to entry that a small "garage" company can spin up something like SQL Server. Maybe as that company grows past the "cheapest VPS on the market" phase they look to running their own Windows servers or (I presume, better yet to Microsoft) let Azure manage SQL Servers for them...
That said, they'd still have to come up with a much cheaper license for SQL Server to entice that "cheapest VPS on the market" crowd, but certainly this appears a step in that direction.
Is it actually used by a meaningful amount of people and businesses?
On average I've seen better windows server setups then Linux setups simply because windows servers tend be used in 'enterprise' solutions.
Maybe this is meant to fight off postgres and -- more importantly -- Oracle.