Great point - it would be nice if they separated out their monetization products (Swarm, Docker Datacenter, etc) from the core Docker engine. There is plenty of money to be made from enterprise customers who will want the security features of Docker Datacenter, or support for Swarm, without bundling your orchestration layer with the container runtime engine.
This type of bundling reminds me of Microsoft bundling IE with Windows. Initially, IE was much worse than Netscape, and this seems like roughly the same thing - monopoly in one market bundling an inferior product to try and achieve a monopoly in another somewhat related market.
I wish they didn't have to cram it all into single product docker though.