Single cloud has a few extraordinary benefits for slow moving organizations.
Once you hang up the sign and declare "we are an xxx shop" it becomes an extraordinarily effective tool to drag unsophisticated employees and departments into the future.
"Microsoft said we have to do this so we have to" overcomes a LOT of internal barriers to technical change.
The biggest problems are never technology in large organizations, it's the humans beings anxiously protecting their overpaid managerial role. Single cloud is amazingly effective at improving the human factor.
At more sophisticated places with a bigger human appetite for innovation of course it's a different story.