I happen to favor the GPL for a number of reasons but there are a number of other, perfectly valid, open-source licenses. It's interesting that some say that BSD doesn't require EnterpriseDB to publish their source code. But, BSD doesn't prevent them from publishing their source code either. For that matter, there's nothing preventing Oracle from publishing their source code save their desire to be a closed-source, proprietary product.
Let's see, the Oracle code that executes PL/SQL is closed and proprietary. The EnterpriseDB code that executes PL/SQL is closed and proprietary. It seems to me that EnterpriseDB is more akin to Oracle than it is to PostgreSQL, the base upon which it is built.
It's great that EnterpriseDB contributes back to PostgreSQL, but that's not the raison d' etre of their business. Their business is selling proprietary solutions to compete against Oracle. Those solutions consist of closed-source software and that makes them a closed-source company.
I suggest their participation in open-source conferences be based on the PostgreSQL tracks and their contributions to that project. Their EnterpriseDB product and messaging should be given the same consideration that the Oracle database would be given. Sorry, Andy.