Its getting hard to keep saying blockchain for everything in this space, so I'll just start referring to it as the distributed ledger ecosystem. Azure Blockchain as a Service has become a very diverse ecosystem hosting a wide variety of technologies.
Open, is perhaps what best describes the current environment: A place for partners to put new platforms, frameworks, tools and services for curious customers to discover and experiment with. What is the best way to find out how well a consensus protocol performs in a geographically distributed network? Azure of course! What is the right platform to test out a wild idea for distributed ledger technology without breaking the bank (pun intended)? Azure of course! How should you go about testing a particular platform against your functional and non-functional requirements? Azure of course!