I don't see how having "some proprietary code that they would like to keep proprietary" is "completely and totally unrelated to" "not want[ing] to have to owe [someone/anyone] source code to internal systems"?
I don't see how having "some proprietary code that they would like to keep proprietary" is "completely and totally unrelated to" "not want[ing] to have to owe [someone/anyone] source code to internal systems"?