Its not as simple really. X Server being work on so much and being partially open was because DEC and co were in a panic that Sun would turn NeWS into a second

Its not as simple really. X Server being work on so much and being partially open was because DEC and co were in a panic that Sun would turn NeWS into a second NFS. NeWS also could and did run on some other Unixes. So really a lot of the history has to do with complex pissing context between different vendors that eventually escalated into full blown Unix wars.