I understand their Enterprise offering offsets the costs of hosting the open source version for you. But should another product be the dependency of determining if the open source version is free? What if the Enterprise offering stops making money? Wouldn't you rather pay for the service you use so it supports future development? It's like Apple depending on product A to give away B for free, that doesn't seem like it'd scale a whole lot. Product B will just reach into the resources needed to build and manage product A.

Just my 2c anyways, happy to hear feedback on why I'm wrong :)