This can be a very real loss. Third party contributions are driven by specific needs. When the license changes too much, those third parties can either pay for

This can be a very real loss. Third party contributions are driven by specific needs. When the license changes too much, those third parties can either pay for a fork (with money/time investment) and improve their own modifications or get the enhancements in the upstream product without any improvements of their own. There is a middle ground with paid source code access, but I don't see a lot of commercial offerings do that.