BPMN21 — Please clarify if the usage of a XOR Join is not redundant

Software vendors seem to implement it as a mandatory step to close every XOR Gateway with a XOR Join.
It seems that even the majority of users which can be found in the internet, assume or state that the XOR Join element has to used everytime a XOR Gateway is opened.
Just a few sources state that the usage of the XOR Join gateway is optional.

Since i don't see a definitie logical reason, to use the XOR Join gateway at all, i was researching the OMG BPNPs specifications, which seem not to clrarly state how to handle XOR Joins either.
Therefore i open up this issue. Could you please state:

1. is there really an imgainable situation, in which the XOR Join makes sense? Is this element really needed?
2. What is your recommendation in usage?

Thank you very much for any clarification