Bait and switch
I sympathize with a business who develops software and releases it as open source, only to later find other businesses undercutting them with their own software. But I think they must have known that was a likely outcome, and the idea that they could lock customers into a new, proprietary deal after hooking them on freedom is just wrong. Although Red Hat have switched to the, well, grey side if not actually dark, I think their remarkable and well deserved success proves that you can develop free software on the back of customer support.