Microsoft have made a problem for themselves with the Virtualisation Tax (aka Software Assurance) you have to pay when running SQL Server in the Cloud.

I must stress this is not a technology issue. It is a financial issue. If you compare Enterprise Edition features with (for example) Redshift for a new server, Redshift can give what you need for a fraction of EE costs.

DB staff do have some influence over what technology is used, but so do the bean counters. It is very hard to make a case for a new EE instance in AWS when the competition is Redshift. Add to this that AWS product managers are tasked to reduce product costs twice a year then the business case for SQL Server becomes weaker as time goes by.

SQL Server is a great product, but current licensing costs have pushed it into the high-end price bracket, opening up the same sort of price/feature hole in SQL Server that Microsoft used in the past to attack the other major players.