Seeing how SQL is not a programming language, this list is bunk.
Maybe not, but I used to build a lot of powerful, blazing-fast Transact-SQL stored procedures that contained a large percentage of a small investment management firm's business logic. It kept them committed to SQL Server, true, but it wasn't like they would have benefitted from switching to Oracle or MySQL, anyway.
Most developers use about 5% of Transact-SQL's capabilities.