Companies don't open source their products, especially their core business products, because they are awesome and want to contribute to the community (at least

Companies don't open source their products, especially their core business products, because they are awesome and want to contribute to the community (at least the majority of for-profit ones). They do it because: * The users demand it (you can be sure that MongoDB wouldn't be even remotely as popular if it started life closed-source) * Because it generates free marketing and helps build a community * Because it allows paying developers less or attract stronger talent * Because it allows leveraging the community's talents to make the code better (I.E. getting outside contributors) When you change the license, you break the unspoken contract between your users and contributors and the company, which is just a form of bait and switch.