That's not a comment on the technical benefits. It's a comment on turning around battleships.
Porting large projects is lots of work, especially when there's plenty of stuff to do that directly impacts the customer. New projects are a different story.
And it's not even necessarily a good idea to port large projects - completely ignoring the complexity of doing a port while continuing further development and maintenance on an existing product.
Porting large projects is lots of work, especially when there's plenty of stuff to do that directly impacts the customer. New projects are a different story.